Session EA: Conference Experience for Undergraduates Poster Session (14:00-15:30)

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Abstracts
Chair: Warren Rogers, Westmont College
Room: Sweeny E





EA.00001: Resistive Plate Chamber half-octant production for the PHENIX Forward Trigger Upgrade
Phillip Abernethy

PHENIX studies polarized p+p collisions produced by the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory to better understand the spin structure of a proton. PHENIX is upgrading the forward muon trigger by adding new Resistive Plate Chambers (RPC's). The RPC's will provide the ability to trigger on high p{\_}T single muons. RPC Station 3 consists of sixteen half-octants, each with three modules containing gas gaps. Before the half-octants are assembled, each module must be tested for Quality Assurance (QA). After each module is approved they are mounted with Front End Electronics (FEE) boards to amplify and discriminate the signals for output. Once approved, a three module set is installed into a half-octant shell and the cables are routed so as to minimize additional noise. The half-octants are then evaluated and tested for dark current, gas leaks, and noise levels. This poster will describe the process of assembly and Quality Assurance for each half-octant.    [Preview Abstract]

 



EA.00002: Proton Accelerator for Calibration of Silicon Detectors for Neutron Decay
Mark Abotossaway , Jeff Martin , David Harrison , Micheal Gericke , Kumar Sharma , Graham Schellenberg

There is a new generation of neutron beta-decay experiments being conducted where both decay electrons and protons will be detected. The Nab Experiment at the Spallation Neutron Source (in Oak Ridge, TN) is an example of one such experiment. In Nab, protons resulting from the decay will be post-accelerated to 30-keV by a static electric field. Custom segmented silicon detectors with a very thin dead layer are being manufactured to detect the protons. For testing and calibration of the Si detectors, and proton detectors in general, a 30 kV proton accelerator has been constructed at the University of Manitoba. The accelerator is based on the Manitoba II double focusing mass spectrometer, which was modified for our purposes. Details of the modifications will be presented along with a discussion of future work. Results collected with a commercial Si Surface Barrier detector and radioactive sources investigating Si detector resolutions in the tens of keV range will also be presented.    [Preview Abstract]

 



EA.00003: Development of GEM Detectors for OLYMPUS and Analysis of Experimental BLAST Data
Matthew Anthony , Laura Havener

OLYMPUS is a precision experiment that investigates the two-photon contribution to elastic lepton scattering. It is based on the existing BLAST detector to precisely determine the trajectories of charged particles. This apparatus does not cover the forward angle regions where elastic scattering will be used to monitor the luminosities. Therefore, precise tracking detectors will be placed in these positions. GEM (Gas Electron Multiplier) detectors incorporate Cu layer-sandwiched Kapton foils with a chemically etched micro-hole pattern for gas amplification. A test chamber for GEM detectors was produced to test performance of GEM foils and the readout. A ROOT data analysis project was carried out in preparation for a publication of BLAST experimental data. Graphs were produced for the new measurements of the deuteron tensor analyzing powers T20 and T21 and the separated charge (Gc) and quadrupole (Gq) form factors as a function of four-momentum transfer in comparison with existing data and various theoretical descriptions.    [Preview Abstract]

 



EA.00004: Adaptation of Crystal Ball and TAPS Detectors for Efficient Data Acquisition at MAMI
Joseph Asercion

To prepare the experimental apparatus at MAMI for the next set real photon experiments, the Crystal Ball and Two Armed Photon Spectrometer (TAPS) detector systems needed to be optimized for better performance. The Crystal Ball and TAPS particle detectors at MAMI employs object-oriented data acquisition architecture based on the C++ language as well as CERN's ROOT library. This system, utilized by the A2 collaboration at the institute, has been adequate for past experiments; however, it has recently proven to be more and more unstable. To alleviate this problem, the data acquisition software was rewritten as a more cohesive architecture, allowing for greater flexibility in experimental parameters and a decrease in instability. In addition to restructuring the software system, new Gas Electron Multipliers (GEMs) were investigated for use with the Crystal Ball as signal amplification devices using generated voltage signals to test feedback efficiency. These modifications are necessary to provide improved signal detection and data acquisition in future experiments.    [Preview Abstract]

 



EA.00005: Analysis of an Experiment on Neutron-rich Isotopes
S. Ash , M. Warren , N. Frank , G. Christian , A. Gade , A. Spyrou , M. Thoennessen , T. Baumann , G.F. Grinyer , D. Weisshaar , P.A. Deyoung

The structure of neutron-rich nuclei far from stability is of particular interest in evaluating theoretical models of the nucleus. Recently the neutron-unbound nucleus of $^{28}$F was produced via one-proton stripping from a $^{29}$Ne beam at the National Superconducting Cyclotron Laboratory at Michigan State University; this nucleus is one neutron away from the magic number N=20. In addition to $^{28}$F, other isotopes were produced from secondary fragmentation of $^{32}$Mg, the primary beam contaminant. Since $^{28}$F is neutron-unbound in its ground state, it immediately decays in to a neutron and $^{27}$F. The CAESAR CsI array surrounded the $^{9}$Be reaction target to measure gamma-rays emitted from $^{27}$F in a bound excited state. The outgoing charged particle and decay neutron were measured in coincidence. The neutrons were detected by the MoNA, and the charged fragments were swept by a magnet into a series of charged particle detectors. The analysis requires separation and identification of both charged particles and neutrons. The isotope identification for charged particles is obtained from time-of-flight measurements after correction up to the fourth order for dispersive angle and position after the magnet. This isotope separation technique and current analysis status will be presented.    [Preview Abstract]

 



EA.00006: Monte Carlo Simulations for Future Geoneutrino Detectors
Morgan Askins

The main contribution of heat in the earth's mantle is thought to be the radioactive decays of 238U, 232Th, and 40K. A precise measurement of the levels of 238U and 232Th can be determined by measuring the flux of electron anti-neutrinos (geoneutrinos) emitted from their decay chains. Although detectors such as kamLAND and Borexino have detected few geoneutrinos, a new cost effective geoneutrino detector is proposed which takes advantage of the total internal reflection within a long rectangular prism acrylic container of liquid scintillator having a single photomultiplier tube (PMT) on each end. An array of these containers would allow for a large scintillator volume relative to the number of PMTs, but could have a lower radio-purity. The event signatures of these decays were compared to those from neutrino interactions using Monte Carlo simulation software based upon GEANT4. In this poster I will discuss the limitations which arise from this design such as, the thickness of the acrylic container which causes high loss of optical photons due to scattering and absorption, rod length which results in higher scattering rates within the scintillator, and size of the array.    [Preview Abstract]

 



EA.00007: MoNA and Two-Neutron Decay Analysis
Amanda Grovom , Alegra Aulie , Warren F. Rogers

The Modular Neutron Array (MoNA) is a large, high-efficiency position-sensitive neutron detector array housed at the National Superconducting Cyclotron Laboratory at Michigan State University, consisting of 144 2-meter long scintillator bars with a PMT positioned at each end, designed to detect the energy and trajectory of fast neutrons emitted in the breakup of exotic neutron-rich nuclei. Because a single neutron can scatter multiple times within MoNA, (including a large presence of dark-scattering from Carbon), the experimental challenge to distinguish between single and multiple neutron decay events is significant. We've developed special data-sorting routines that selectively filter on a combination of factors such as neutron velocity and scattering angle, hit-pattern distribution, neutron-fragment opening angle, and decay energy in order to reduce the Carbon scattering background and enhance correlations between pairs of neutrons. We've applied this analysis to the 2-neutron decays of $^{24}O$ and $^{13}Li$ from data sets from previous MoNA experiments. Results will be presented.    [Preview Abstract]

 



EA.00008: Measurement of Neutron Reflectivity from a Silicon Crystal: Preparation for an nMDM Measurement
Benjamin Barber , Donald Koetke , Muhammad Arif , Michael Huber

Physicists from ANL, Valparaiso University, University of Hawaii, and NIST have designed an experiment to use the known neutron magnetic dipole moment (nMDM) to measure Schwinger scattering in Si, a process whereby the orientation of the magnetic dipole polarization is altered by interactions with the atomic electric fields in a Si crystal. This measurement is intended to be a precursor to a search for a neutron electric dipole moment (nEDM) employing a similar spin rotation via a different interaction. Both measurements depend on neutron Bragg reflections down a slotted Si crystal. For a successful measurement, the neutron beam has to reflect approximately 150 times, without a large loss of beam intensity. This requires a high reflectivity, on the order of 99\% reflective. In order to make an accurate measurement of the Schwinger scattering, both the incident neutron beam and the crystal's reflectivity need to be well understood. This summer we have characterized the newly commissioned ``nMDM Experiment'' neutron beamline at the NIST Center for Neutron Research, and have measured the reflectivity of the slotted Si single crystal intended for the experiment. These measurements lay the groundwork for the coming nMDM Schwinger scattering measurement.    [Preview Abstract]

 



EA.00009: The Partial Wave Decomposition of the Meson Spectrum
Stacy Barker , Dennis Weygand , Gerard Gilfoyle

The spectrum of hadrons provides important insight to the low-energy, non-perturbative regime of Quantum Chromodynamics (QCD), the theory of the strong interaction. Meson states are particularly interesting due to their binary structure; most mesons appear to composed of a quark-antiquark pair. However, measurement of the meson spectrum in confounded by the broad and overlapping nature of these states. The technique of partial wave analysis (PWA) has been used to successfully decompose these states from the parameters of their decay in limited kinematic regimes, usually high energy and low momentum transfer. To exploit PWA at low energy, for example at CEBAF, the analysis becomes more compute intensive. Here we report on techniques of PWA in a distributed compute environment, using the CLARA platform, a java-based service oriented architecture (SOA) being developed for the CLAS12 offline analysis environment.    [Preview Abstract]

 



EA.00010: Transverse energy at RHIC in the forward/backward directions using the PHENIX Muon Piston Calorimeter
Jonathan Ben-Benjamin

The status of a measurement of transverse energy $E_T=Esin(\theta)$ in the forward direction ($3.1 < |\eta| < 3.7$) from Au+Au, p+p, and d+Au collisions at RHIC energies using the PHENIX Muon Piston Calorimeter will be reported. Transverse energy has not been measured in this kinematic range at these beam energies before. This result can be used to estimate energy density in heavy ion collisions. In addition, fluctuations in this observable can be used as a signature for a critical point in the phase diagram of nuclear matter. Finally, measurements of transverse energy can be used to discriminate between competing models of hadronic interactions.    [Preview Abstract]

 



EA.00011: Effect of Temperature on Niobium Surface Morphology during Buffered Electropolishing
Jennifer Beveridge , Andy Wu

To achieve high acceleration gradients for particle accelerators based on niobium (Nb) superconducting radiofrequency (SRF) technology, Nb cavity surfaces must be as smooth and as free from imperfections as possible. Presently, removing the imperfect Nb surface layer is performed by buffered chemical polishing (BCP) or electropolishing (EP). Buffered electropolishing (BEP), a method developed at Jefferson Laboratory, has been shown to outperform both BCP and EP in terms of surface smoothness and polishing rate. BEP utilizes HF, H$_{2}$SO$_{4}$, and lactic acid to etch away the damaged Nb surface layer. The mechanism for the Nb removal from the surface was studied, as well as how the Nb surface morphology changed with temperature. BEP was performed on Nb at temperatures between 7\r{ }C and 44\r{ }C and the surface smoothness was evaluated. To investigate the role of lactic acid in BEP, soluble Nb complexes with lactic acid were proposed and an electrolyte consisting of H$_{2}$SO$_{4}$ and lactic acid was used to electropolish Nb. Results indicate that higher temperature during BEP yields faster polishing rates, maximizing near 32\r{ }C, and that a smoother Nb surface can be obtained by polishing between 21\r{ }C and 32\r{ }C. In addition, results suggest lactic acid may form soluble coordination compounds with niobium, aiding HF in Nb removal from the material surface.    [Preview Abstract]

 



EA.00012: Parton Cascade Initial Conditions for Event-by-Event Hydrodynamic Modeling at RHIC
Vivek Bhattacharya , Hannah Petersen , Steffen Bass

Relativistic heavy-ion collisions at RHIC are believed to have replicated the state of the early universe by creating a quark- gluon plasma, a deconfined phase of QCD. One of the most interesting findings at RHIC is that the QGP behaves like a near-ideal fluid. As a result, hydrodynamic calculations are used to model the evolution of the QGP, but recent work shows that these calculations are very sensitive to initial conditions (ICs). Common Glauber and Color Glass Condensate ICs are calculated at the start of the collision and do not treat the pre-equilibrium evolution of the system. Here, we improve upon these ICs by employing a Parton Cascade Model, used to describe the evolution of a deconfined system during the early pre-equilibrium phase of the reaction, to accurately evolve the system from the start of the collision to the beginning of hydrodynamic evolution. Furthermore, we adopt a Gaussian smoothing framework to create event-by-event as well as event- averaged ICs. We present various ICs and study the results generated by this hybrid PCM/hydrodynamic model in terms of both average quantities and event-by-event fluctuations.    [Preview Abstract]

 



EA.00013: Construction of a Variable Degrader for Optimization of $^{8}$Li in Beta-Neutrino Correlation Experiments
J. Boulding , K.S. Sharma , R.E. Segel , N.D. Scielzo , G. Li , F. Buchinger , J.A. Clark , G. Savard

Information about neutrinos is difficult to attain due to their very low interaction rate with matter. However, we can reverse engineer this information using kinematical reconstruction of the decay process. Using an 18 MeV $^{7}$Li beam striking a $^{2}$H gas target, a product beam of $^{8}$Li is created. A beam stop stops the primary $^{7}$Li beam and the $^{8}$Li beam travels through a variable degrader and a large solenoid into a helium gas catcher. Lithium hydroxide is extracted and moved down the beamline into a 2.5 T Isobar separator magnet. Applied radiofrequency fields break the LiOH to $^{8}$Li, which is then delivered to the Beta-decay Paul Trap. Double sided silicon strip detectors are used to detect the beta and double alpha decays inside the trap. Info about the direction and energy of the alpha and beta particle can be used to determine the direction and momentum of the $^{8}$Li atom and the neutrino released during the decay. Previous experiments were designed to optimize the yield of $^{8}$L and resulted in a beta-alpha-alpha coincidence rate of 1 per second. The addition of the variable degrader to the experimental setup increased yields by approximately 30\%. Supported by: NSERC, Argonne National Lab and the University of Manitoba.    [Preview Abstract]

 



EA.00014: Investigating Parton Energy Loss and Antishadowing in Nuclei at Fermilab E-906/SeaQuest
Brandon Bowen

Fermilab E-906/SeaQuest is a fixed target experiment using Fermilab's Main Injector optimized to detect muon pairs produced in 120 GeV proton collisions. Primarily, SeaQuest will measure the Drell-Yan di-muon cross sections for proton-proton and proton- deuterium collisions for extracting $\bar{d}$ to $\bar{u}$ asymmetry in the nucleon. This data will also be used to understand partonic energy loss in cold nuclear matter, which will aid in understanding partonic energy loss in hot nuclear matter experiments at the LHC and RHIC. Since parton energy loss is inversely proportional to the beam energy, SeaQuest will be much more sensitive to energy loss effects than Fermilab E-866/NuSea, which placed upper limits on such parton energy loss at 800 GeV. SeaQuest will also further our understanding of nuclear anti- shadowing and extend the Drell-Yan measurements into the EMC effect region. SeaQuest will have significantly better precision and extension over a higher range in Bjorken-x, where competing asymmetry models diverge strongly from each other.    [Preview Abstract]

 



EA.00015: Background Reduction Techniques for Ultra-low Background Physics
Michael Brown , Reyco Henning , Sean MacMullin

Background reduction receives much attention in neutrino studies and dark matter searches as the events being detected are extremely rare. Knowing your backgrounds well and using extremely low radioactive materials in production are two methods used in such experiments. At the Triangle Universities Nuclear Laboratory the neutron cross section for neon, a candidate material for detecting dark matter, was investigated using energies relevant to backgrounds in these experiments. Also a Monte Carlo simulation was run using MCNPX to determine the best shielding material for keeping detector materials from being activated by high energy cosmic rays. Methods and results for the experiment and simulation will be presented.    [Preview Abstract]

 



EA.00016: Development of a Beam Intensity Detector
Justin Browne , Wolfgang Mittig

The Active Target Time Projection Chamber (AT-TPC) at Michigan State University (MSU) will be filled with a gas that is used as both the target and the detector. To determine the intensity of the beam as it enters the chamber, a detector must be placed immediately upstream of the AT-TPC. The beam intensity is measured by passing the beam through a foil and measuring the amount of ionization in the foil. Because the signal from the primary electrons would be too weak, the electrons are multiplied in a Multichannel Plate (MCP) detector. The electrons are transported out of the beam path to the MCP by electric and magnetic fields.    [Preview Abstract]

 



EA.00017: Computer Code for Calculating Matrix Elements and Overlaps of States for the Generalized Seniority Scheme via Recurrence Relations
Ke Cai , Mark Caprio , Fengqiao Luo

The generalized seniority approximation provides a truncation scheme for the nuclear shell model based on building the states of the nucleus from nucleon pairs. We developed a computer code to calculate matrix elements of one-body and two-body operators between generalized seniority states and overlaps of these states based on a set of recurrence relations. The main steps in our implementation of the computer code consisted of: (1) Developing an object-oriented framework for storing information on generalized seniority states; (2) Applying the symmetries of the problem and caching intermediate results to avoid repeated calculations; (3) Performing extensive validations. The code can be used to calculate matrix elements of operators of physical interest, e.g., the Hamiltonian and electromagnetic transition operators. Planned applications of the code include testing the structure of nucleon pairs and studying the mapping of shell model onto the Interacting Boson Model. Supported by the US DOE under grant DE-FG02-95ER-40934.    [Preview Abstract]

 



EA.00018: Development of a Computing Cluster At the University of Richmond
J. Carbonneau , G.P. Gilfoyle , E.F. Bunn

The University of Richmond has developed a computing cluster to support the massive simulation and data analysis requirements for programs in intermediate-energy nuclear physics, and cosmology. It is a 20-node, 240-core system running Red Hat Enterprise Linux 5. We have built and installed the physics software packages (Geant4, gemc, MADmap...) and developed shell and Perl scripts for running those programs on the remote nodes. The system has a theoretical processing peak of about 2500 GFLOPS. Testing with the High Performance Linpack (HPL) benchmarking program (one of the standard benchmarks used by the TOP500 list of fastest supercomputers) resulted in speeds of over 900 GFLOPS. The difference between the maximum and measured speeds is due to limitations in the communication speed among the nodes; creating a bottleneck for large memory problems. As HPL sends data between nodes, the gigabit Ethernet connection cannot keep up with the processing power. We will show how both the theoretical and actual performance of the cluster compares with other current and past clusters, as well as the cost per GFLOP. We will also examine the scaling of the performance when distributed to increasing numbers of nodes.    [Preview Abstract]

 



EA.00019: Measurement of the 187Re(n,2n)186mRe Destruction Cross-section
C.R. Casarella , J.H. Kelley , R. Raut , C. Howell , G. Rusev , A.P. Tonchev , E. Kwan , W. Tornow , H.J. Karwowski , S.L. Hammond , F.G. Kondev , S. Zhu

We are continuing a program to measure cross sections for $^{187}$Re(n,2n$\gamma$) reactions with particular interest in confirming a transition that has tentatively been identified as a doorway transition feeding the $^{186}$Re E$_x$=149(7)~keV isomeric state. The cross sections are being measured using pulsed, nearly mono-energetic neutron beams, as well as an array of planar HPGe $\gamma$-ray detectors. At present, the reaction cross sections for $^{187}$Re(n,2n$\gamma$) are poorly known, so measuring the cross sections have positive implications, for example, on reactor physics since Re is a common fission fragment. Furthermore, refining the cross section measurements may reduce uncertainties in the Re/Os cosmochronometer. Funding provided by NSF grant NSF-PHY-08-51813.    [Preview Abstract]

 



EA.00020: Investigation of even-even Gd nuclei using the (p, t) reaction
Danyi Chen , Con Beausang , Richard Hughes , Timothy Ross , Jack Shaw , Benjamin Pauerstein

Gadolinium nuclei between A=152 and A=158 undergo a rapid shape change, from spherical to deformed and are therefore interesting in nuclear physics studies. Experiments were performed at the 88 inch Cyclotron at Lawrence Berkeley National Laboratory using the STARS (Si-Telescope Array for Reaction Studies)/ Liberace (Livermore Berkeley Array for Collaborative Experiments) setup. Targets of 154Gd, 155Gd, 156Gd, and 158Gd were bombarded with 25 MeV protons. My research focused on 152Gd, 154Gd, 156Gd nuclei populated via (p, t) reactions and the work utilized a triton-gamma matrix for each nucleus. I am interested in the high energy ($\ge $2.5MeV nucleus excitation energy) part of the triton spectrum when gated by different low lying (yrast and non-yrast) gamma rays which I examined by measuring the slope. I also studied the position and intensity of the large peak-like structure lying close to the pair gap at 2.5 MeV and how it changes for N = 88, 90, and 92. DOE: DE-FG02-05 ER41379 {\&} DE-FG52-06 NA26206 (UR), DE-AC52 -7NA27344 (LLNL), and DE-AC02-05CH11231 (LBNL).    [Preview Abstract]

 



EA.00021: Performance of Object-Oriented Real-Time Control and Acquisition Software
Andrew Collins

The dead-time of the Object-oriented Real-time Control and Aqcuisition data acquisition software, \textsc{orca}, was quantitatively determined for a VME-based system utilizing a single, peak-sensing CAEN 785N analog-to-digital converter and two scaler modules. A single board computer in the VME crate controls rapid read-out of the modules and the data is then transferred via TCP/IP to the \textsc{orca} control program, running on MacOSX, where the data can be filtered based on desired criteria, saved in an open format, and displayed on-line in histograms. A graphical interface allows the system to be configured via ``drag and drop'' method. The performance tests were performed on \textsc{orca} and two other data acquisition systems used at Triangle Universities Nuclear Laboratory, \textsc{coda} and SpecTcl, to compare the systems' data collection capabilities and determine whether the new system is a worthy competitor of the existing systems.    [Preview Abstract]

 



EA.00022: High Speed Readout of the Cathode Signal for the NIFFTE TPC
Brandon Coombes

The goal of the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) is to use a Time Projection Chamber (TPC) to improve the precision of the measurements of the major actinides cross sections. To make these high precision cross section measurements, the start time of each fission event needs to be determined from the TPC cathode with less than 1ns resolution. High speed readout of the cathode signal allows the longitudinal postion of the fission fragment track to be more accurately reconstructed. The current readout TDCs give about 20ns timing resolution. To improve the timing resolution, a new scheme was developed where the cathode signal is split and allowed to propagate through delay lines of different lengths. Then all of the signals are analyzed to better determine the start time. This poster will concentrate on the design and testing done to improve the timing resolution and how this will improve the quality of track reconstruction of these fission events.    [Preview Abstract]

 



EA.00023: $\alpha$-Clusters in $^{16}$O
P.A. Copp , S.R. Lesher , A. Aprahamian , S. Almaraz , B. Bucher , M. Couder , X. Fang , F. Jung , W. Lu , N. Paul , A. Roberts , W.P. Tan , G. Golding , Y. Scachar , N. Ashwood , M. Barr , N. Curtis , M. Freer , J. Malcolm , C. Wheldon , V. Ziman

There has been previous experimental evidence of an interesting four $\alpha$ linear configuration in $^{16}$O [1]. At the Notre Dame FN Tandem Accelerator we explored the reaction of $^ {12}$C+$\alpha$$\rightarrow$$^{16}$O$\rightarrow$$^{8}$Be+$^{8} $Be. An array of Si strip detectors was set up at the forward angles to observe the final individual four $\alpha$- particles [2]. Afterwards, from the $^{8}$Be+$^{8}$Be channel, an excitation curve was constructed for an energy range of 12- 20 Mev. In addition a $^{12}$C ($\alpha,n$) transfer reaction was carried out to study the same $\alpha$-cluster structure in $^{16}$O, which required additional neutron detectors placed at the backward angles. Interesting $\alpha$-cluster levels detected in the two reactions will be analyzed in detail (such as the angular distribution). The preliminary results on the existence of the linear $\alpha$ structure will be presented.\\[4pt] [1] P. Chevallier {\it et al.}, Phys. Rev. {\bf 160}, 827 (1967).\\[0pt] [2] P.J. Haigh {\it et al.}, J. Phys. G: Nucl. Part. Phys. {\bf 37}, 035103 (2010).    [Preview Abstract]

 



EA.00024: Verification of 3D Dose Distributions of a Beta-Emitting Radionuclide Using PRESAGE$^{\mbox{{\textregistered}}}$ Dosimeters
Mandi Crowder , Ryan Grant , Geoff Ibbott , Richard Wendt

Liquid Brachytherapy involves the direct administration of a beta-emitting radioactive solution into the selected tissue. The solution does not migrate from the injection point and uses the limited range of beta particles to produce a three-dimensional dose distribution. We simulated distributions by beta-dose kernels and validated those estimates by irradiating PRESAGE$^{\mbox{{\textregistered}}}$ polyurethane dosimeters that measure the three-dimensional dose distributions by a change in optical density that is proportional to dose. The dosimeters were injected with internal beta-emitting radionuclide yttrium-90, exposed for 5.75 days, imaged with optical tomography, and analyzed with radiotherapy software. Dosimeters irradiated with an electron beam to 2 or 3 Gy were used for calibration. The shapes and dose distributions in the PRESAGE$^{\mbox{{\textregistered}}}$ dosimeters were consistent with the predicted dose kernels. Our experiments have laid the groundwork for future application to individualized patient therapy by ultimately designing a treatment plan that conforms to the shape of any appropriate tumor.    [Preview Abstract]

 



EA.00025: UCN Production from Solid Oxygen Confined in Amorphous Carbon
Chris Cude-Woods , Chen-Yu Liu , Daniel Salvat , Gregory Manus , Aaron Couture

The utility of Ultra-Cold Neutrons (UCN) in fundamental physics has been constrained by the difficulty of producing them in sufficiently high density. This has led to an interest in the development of improved UCN sources. Solid oxygen has shown promise over previous super-thermal sources as a UCN converter and has several advantages, including small nuclear absorption, unique magnetic properties, and lack of incoherent scattering. Our group's previous work has demonstrated a prototype bulk solid oxygen converter and an apparatus to study its performance as a function of temperature. Using a slightly modified apparatus--benchmarked with bulk solid oxygen-- our present study tests a new source that~confines oxygen within a carbon ``nano-pore'' matrix. By freezing oxygen in confinement, we seek to suppress the~$\alpha $ to $\beta $ phase transition, thus extending the higher production cross-section of $\beta $-oxygen to lower temperatures, thereby increasing UCN~yield. We have carried out a UCN production experiment at FP12 at Lujan Neutron Center at Los Alamos National Laboratory in the summer of 2010. The results of the analysis and simulation will be presented in this poster.    [Preview Abstract]

 



EA.00026: Gadolinium Doped Water Cherenkov Detector for use as Neutron Detector
Patrick Davis , Brian Woltman , Dongming Mei , Yongchen Sun , Keenan Thomas , Oleg Perevozchikov

Background characterization is imperative to the success of rare event physics research such as neutrinoless double-beta decay and dark matter searches. There are a number of different ways to measure backgrounds from muon-induced processes and other forms of high energy events. In our current research, we are constructing a research and development project for the feasibility of a Gadolinium doped water Cherenkov detector as a neutron detector. We are constructing a 46 liter acrylic housing for the Gd-doped water consisting of two acrylic cone sections connected to a middle acrylic cylinder to increase volume while still using 5 inch photo multiplier tubes (PMTs) on either end. I will present the challenges of a Gd-doped water detector and the reasons why our design should be much more successful than past metal housed detectors. I will also discuss our current progress and future goals of our detector including its use in characterizing the background in the future underground laboratory in the Sanford Lab, soon to be DUSEL.    [Preview Abstract]

 



EA.00027: CdWO$_{4}$ and CsI Crystal Detectors
Alyssa Day , Dongming Mei , Yongchen Sun , Keenan Thomas , Oleg Perevozchikov

CdWO$_{4}$ scintillators were proposed for detecting geo-neutrino, neutrinoless double-beta decay, and dark matter. I used the energy resolution of three different sized CdWO$_{4}$ crystals for detecting $\gamma $-rays. The three crystals had diameters of 19mm but thicknesses of 5mm, 9mm, and 19mm. In using the 19mm CdWO$_{4}$ crystal, the energy resolution of a $^{137}$Cs source resulted in 11.4{\%} at 662 keV, and 6.5{\%} at 1173.2 keV and 8.6{\%} at 1332.5 keV for $^{60}$Co. As the sizes of the thickness decreases, a slight deterioration in energy resolution occurred with more Compton scattering in the energy spectrum. A CsI(Tl) crystal was also used for comparison; this crystal was 19mm in thicknesses and length. This crystal had an energy resolution for $^{137}$Cs of 12.3{\%} at 662 keV, 5.3{\%} at 1173.2 keV and 6.6{\%} at 1332.5 keV for $^{60}$Co. The CsI(Tl) crystal capable of measuring low energies in which x-ray peaks were visible with some sources. The CdWO$_{4}$ crystal was more beneficial when measuring gamma-ray energy close to 511 keV that is primary signature from geo-neutrino detection with $^{106}$Cd. Greater Compton scattering occurred with the CsI crystal when detecting higher energies. Using a number of smaller crystals allows for the development and characterization of these crystals.    [Preview Abstract]

 



EA.00028: PIXE Spectrometry for Sediment Characterization
Katherine DeBlasio , Daniel Pesch

This project focuses on the non-point source sedimentation and hypereutrophication problems plaguing Lake Macatawa, Holland, MI. Excess nutrients, such as phosphates, attached to sediments, flow into the lake from the surrounding watershed increasing both the lake's turbidity and nutrient imbalance. The goal is to identify signatures representative of unique locations within the watershed to aid in the determination of sediment provenance and effectively allow for the modeling of this non-point source pollution as multiple point sources of the sediments and their adsorbed nutrients. This is accomplished by characterizing sediment with Particle Induced X-Ray Emission (PIXE) spectrometry. Eighteen different elemental concentrations in sediment samples are measured via PIXE. These concentrations are compared between sites and rain events to find trends in the changes of concentrations of the metals that will help characterize the sediment source.    [Preview Abstract]

 



EA.00029: A study of Jet Quenching near the QCD Phase Transition
Andrea Delgado , Rainer Fries , Ricardo Rodriguez

We study the dependence of jet quenching in quark gluon plasma on the local density of the plasma. Liao and Shuryak* have previously suggested that quenching reaches a maximum for entropy densities around the QCD phase transition. This ``shell-like'' quenching scenario seems to be favored by the large azimuthal asymmetry v$_{2 }$for large momentum hadrons measured at the Relativistic Heavy Ion Collider (RHIC). Our calculations confirm the results by Liao and Shuryak qualitatively, and describe RHIC data on the nuclear suppression factor R$_{AA}$ and v$_{2}$ simultaneously quite well. We then extrapolate to nuclear collisions at the Large Hadron Collider (LHC) using the same density dependence that fits RHIC data. We show that ``shell-like'' quenching gives unique predictions for R$_{AA}$ and v$_{2}$ at LHC. Data from LHC will hence help us to distinguish between different scenarios for the density dependence of jet quenching. *Phys. Rev. Lett. 102,202302(2009)    [Preview Abstract]

 



EA.00030: A Novel Time of Flight Detector for the Pioneering High Energy Nuclear Interaction eXperiment
Richard Dix , Kirk Drummond , William Powell , Mickey Chiu

Time-of Flight (TOF) detectors allow one to identify particles created in collider experiments. The Pioneering High Energy Nuclear Interaction eXperiment (PHENIX) at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory is proposing new forward timing detectors to measure the TOF with a 10 picosecond (ps) timing resolution. A prototype of the detector electronics system was tested by using Cherenkov signals from cosmic rays and translating them into digital signals. Each signal was split and delivered to two analog-to-digital-converters (ADCs). C++ and ROOT were used to write programs to compare voltage readings reported by the two ADC channels and determine the time difference between them, which was 76 ps. Using new ADCs, which run 17 times faster, the timing resolution will be 5 ps. This will allow PHENIX to probe the meson-baryon anomaly at intermediate, transverse momentum by making detailed measurements in a psuedorapidity region which has not been well measured.    [Preview Abstract]

 



EA.00031: Increased Precision of $^{3}$He target's Polarization Determination Through LabView Automated EPR Measurement for Nulcear Physics Experiments
Jessica Doehrmann , G. Laskaris , H. Gao , Q. Ye , W. Zheng , T. Averett , G.D. Cates , W.A. Tobias

Polarized $^{3}$He is used as an effective neutron target in the GDH sum rule, Compton scattering and 3-body photodisintegration experiments. These experiments have been carried out to determine the GDH integral on $^{3}$He from the two-body breakup threshold to the pion production threshold as well as nucleon spin polarizablities and asymmetries. The polarization of the $^{3}$He target is measured through NMR and EPR measurements. To reduce the uncertainties in asymmetries and nucleon spin polarizablities, it is necessary to increase the precision in the measurement of $^{3}$He polarization. In order to achieve this goal, the EPR measurement process was automated by LabView, controlling the electronic instruments through GPIB interface. The calculated $^{3}$He polarization using the LabView program is consistent with the results obtained from NMR water calibration measurements.    [Preview Abstract]

 



EA.00032: Analysis of Electronic Noise in the Majorana Dark Matter Detector
Greg Dooley

The Majorana Experiment seeks to detect neutrinoless double beta decay of $^{76}$Ge with an array of customized ultra pure germanium detectors. It will simultaneously operate in a search for dark matter through direct detection of nuclear recoils with particles in a DM halo. Its ultimate DM goal is to probe down to masses of $<$1 KeV/c$^2$ in a 120 kg Ge detector. Rather than distinguish between nuclear and electron recoil events, the detector will achieve such high sensitivity through extreme reduction of noise and background. Background radiation will be blocked by deploying the device deep underground in the Sanford Underground Laboratory in Lead, SD. Limitations on and methods to reduce electronic noise are explored in this project. The frequency response and total noise of each component is modeled using SPICE. Raw electronic noise signals are taken from the Cogent detector and resolved into series, parallel, and 1/f noise. This procedure is used to help identify ways to improve novel pre-amplifier designs and optimize pulse shaping parameters. It is also used to produce accurate simulations of noise to aid in pulse shape analysis.    [Preview Abstract]

 



EA.00033: Impact of Temperature Changes on Drift Properties in a Straw Tube Chamber
Brent Driscoll

The GlueX experiment at Jefferson Lab will use a straw-tube chamber as part of its charged particle tracking package. This chamber, the CDC, will measure the coordinate of tracks perpendicular to the anode wire to an accuracy of 150 microns, and while the temperature in the experimental hall will be monitored, it will be necessary to account for the impact of temperature changes on the drift properties of the gas being used in the chamber. A study has been performed to map out these properties as a function of temperature in a small prototype chamber at Carnegie Mellon. Cosmic rays have been studied with the chamber operated in the temperature range of 20 to 34 C. These temperature variations have led to measured changes in both the gas and the performance of the electronics. The results will be compared to calculations of the expected behavior and ultimately used in the calibration of the CDC in the running GlueX experiment. I will present details of the test setup, the measurements and the analysis of the data as well as a comparison to the expectations.    [Preview Abstract]

 



EA.00034: The Gas Handling System Assembly for the NIFFTE TPC
Dana Duke

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) uses a Time Projection Chamber (TPC) to obtain more accurate measurements of the fission cross sections of radioactive isotopes such as Pu-239, U-235, U-238, etc. Past cross-section measurements have used various detection methods such as the parallel plate ionization chamber, but by using a TPC, accuracy levels can be improved to sub 1{\%} error. Analysis of TPC data will improve the current understanding of fission dynamics and the fission process. The NIFFTE TPC is located at the 90L beam line at LANSCE-WNR where targets are bombarded with fast neutrons to induce fission. The resulting fission fragments are tracked using gas ionization within the TPC. Gas handling system function and assembly is examined and justified. Major components of the system include solenoid valves, pressure transducers, and mass flow controllers. This gas handling system has the capability of remotely controlling the flow of multiple gas sources into the TPC.    [Preview Abstract]

 



EA.00035: Constructing the Hodoscope Arrays for the Fermilab E-906/SeaQuest Spectrometer
Brianna Edlund

SeaQuest is a fixed-target experiment designed to extract the light antiquark sea structure of the proton at high Bjorken-x. Using 120 GeV/c protons from the Fermilab Main Injector, the experiment will measure the cross section ratio of di-muon pairs produced by the Drell-Yan process with liquid hydrogen and deuterium targets. From this ratio the light antiquark ratio will be extracted. The trigger for the di-muon pairs uses a set of 8 hodoscope planes, the final four of which are the topic of this work. The final four hodoscope planes consist of 128 scintillator paddles and 224 photomultiplier tubes (PMTs). Due to their size, three planes require PMTs on each scintillator end to avoid timing jitter. SeaQuest uses the old PMTs and tube bases from E866/NuSea, plus other experiments, so it was critical to verify the performance of each PMT and base. These tests included operating voltages, noise rates, and rate capability. The methods used will be presented as well as how the results were used to optimize efficiency in the spectrometer's expected high-rate regions.    [Preview Abstract]

 



EA.00036: Method Development of Detecting PeV Gamma Rays Using the IceCube Observatory
Maxim Egorov

We present a method of detecting PeV gamma rays from the Galactic Plane using the IceCube Observatory. IceCube is a cubic km scale Cherenkov ice detector located $\sim $1.4 km under the ice at the geographic South Pole, with a sister component IceTop, a surface air shower array, located directly above it. By selecting extensive air shower (EAS) events with a shower axis that passes through both IceTop and IceCube, it is possible to distinguish CR from gamma ray EAS by their muon content. CORSIKA Monte Carlo simulations of both EAS types are used to develop and test the best cuts for gamma ray and CR separation. All muon-rich EAS are eliminated by cutting out events that trigger IceCube, suppressing the background to consists of muon-poor CR EAS, while falsely rejecting $\sim $20{\%} of the gamma ray signal. We improve the method by separating the remaining $\sim $20{\%} of gamma ray signal from the CR background by analyzing three types of cuts: rectangular, Fisher Discriminant, and Multilayer perceptron (MLP). With the emaining $\sim $20{\%} of gamma ray EAS, the MLP cut is found to give the best results yielding 33.6{\%} signal efficiency for 99.997{\%} background rejection. Overall, MLP improves signal efficiency to $\sim $86.6{\%}.    [Preview Abstract]

 



EA.00037: Investigating the fragmentation of excited nuclear systems
Jennifer Erchinger , L.W. May , P. Marini , S. Wuenschel , S.J. Yennello

Constraints on the symmetry energy, important in the nuclear equation of state, can be provided by examining the isotopic composition of fragments emitted from excited nuclear systems. These fragments can be studied by isotopic scaling (isoscaling) of fragment yields from two sources with different neutron to proton ratios (N/Z). Traditionally, isoscaling compares isotopically identified fragments from two different reactions, requiring an assumption that the N/Z of the source is that of the reacting system or estimated from a model-based correction. Wuenschel \textit{et al.} used emitted charged particles and neutrons to reconstruct quasiprojectile (QP) N/Z. Bins in QP N/Z were used as the sources for the isoscaling analysis instead of different reaction systems. They showed that comparing bins within a system better defines the source N/Z, giving better constrained symmetry energy. The current research takes an in-depth look at bin-to-bin isoscaling and provides optimal delta and source constraints and shows the effects of excitation energy on isoscaling.    [Preview Abstract]

 



EA.00038: The Ursinus College Liquid Hydrogen Target
Nicholas Ferrante , Jessica Palardy , Lew Riley , Remco Zegers

A liquid hydrogen target has been constructed and tested for use in experiments at the National Superconducting Cyclotron Laboratory at Michigan State University. The design is based upon the Japanese liquid hydrogen and deuterium target at RIKEN in Japan. This target will provide a pure hydrogen target with greater proton density than and without the carbon background of polypropylene targets. Characteristics of the target as well as prospects for its use are discussed.    [Preview Abstract]

 



EA.00039: Calibration of CsI Detectors for the NPDG Experiment
Charles Fieseler , Septimiu Balascuta , David Bowman , Chris Crawford , Nadia Fomin , Kyle Grammer , Andrew McNamara , Seppo Pentilla

The NPDGamma experiment at Oak Ridge National Lab will measure the asymmetry in gamma production in the reaction: neutron + proton -$>$ deuteron + gamma. The parity violating component of this reaction is measured from the correlation of neutron spin and $\gamma $ momentum. In order to detect this asymmetry, 48 cesium iodide scintillators are arranged in a cylinder around a liquid parahydrogen target in a beam of polarized neutrons. The detector efficiency was calibrated using a rotating Cs$^{137}$ source of known intensity. The output voltage output as a function of the rotation angle was fit using a Fourier series expansion plus a linear background term. The amplitude was the ratio of signal to energy deposited in V/MeV/s, essentially an efficiency for each detector. The calibration procedure will be presented, as well as the complete data analysis. Supported by NSF under grant PHY-0855584.    [Preview Abstract]

 



EA.00040: Development of an Active Target Time Projection Chamber for Nuclear Reaction Studies with Radioactive Isotope Beams
Michael Ford , Daniel Bazin , William Lynch , Wolfgang Mittig , Daisuke Suzuki

An Active Target Time Projection Chamber (AT-TPC) is being developed at the NSCL. This new detector uses the gas of a time projection chamber as an active target, providing powerful new capabilities for studying reactions induced by radioactive rare isotope beams. The detector design encompasses a dual gas system, providing one gas optimized for electrical isolation of the field cage and another that serves as the target. For versatile use of targets, the detector should operate with a wide range of target gasses including H$_{2}$, D$_{2}$, $^{3,4}$He and Ne at pressures ranging from .2 to 1.0 atm and electric fields up to 1 kV/cm. Gas amplification and signal detection will be achieved with planar Micromegas structures mounted at the end of the gas detector volume. The Micromegas anode plane will be segmented into approximately 10,000 pads and read out by GET advanced active target electronics that are being developed in collaboration with French and Japanese institutes. I will be presenting the current status of the research and development of the AT-TPC and its prototype.    [Preview Abstract]

 



EA.00041: Deuteron Formation for Big Bang Nucleosynthesis Models
Jennifer French , Katrina Koehler , June Matthews , Brian Daub , Mark Yuly , Stephen Wender , Vlad Henzl , Mike Kovash

A measurement of the H(n, d$\gamma )$ cross section at low energy is being performed at the WNR facility at Los Alamos National Laboratory. This deuteron formation experiment is key to improving calculations of the baryon density in Big Bang Nucleosynthesis models. Incident neutron energies are between 100 keV and 1 MeV. The deuterons are created and detected in a plastic scintillator active target. Gamma rays released by the neutron-proton capture reaction are detected in a BrilLanCe detector. Scattered neutrons from n-p elastic scattering detected in two neutron detectors are used for calibrating the active target ADC spectrum.    [Preview Abstract]

 



EA.00042: Improvements to Proton-Carbon Polarimetry at RHIC
Kyle Gainey

The Relativistic Heavy Ion Collider (RHIC) complex at Brookhaven National Lab provides a beam of up to 70\% polarized protons for study of polarized proton collisions to better understand proton spin structure. The RHIC polarimetry group operates and maintains Proton-Carbon (pC) polarimeters which measure the spin of the protons by running a 10$\mu$m wide carbon strip through the beam, detecting recoiling carbon atoms, and calculating the asymmetry in the carbon recoil. This asymmetry is directly proportional to the beam polarization. The carbon strips are made by evaporating carbon with an electron beam. This method produces targets with very limited lifetimes. An advanced method is being developed to lengthen target lifetimes. The laser plasma ablation (LPA) method offers carbon strip targets whose atoms are more isotropically distributed, resulting in a more durable target. With LPA, a laser is pulsed at a carbon disk, the carbon atoms on the surface of the disk become a plasma, and the atoms condense on a slide, forming strips. This poster will focus on RHIC pC polarimetry and the LPA method of making carbon strip targets.    [Preview Abstract]

 



EA.00043: Particle-Induced X-Ray Emission Analysis of Atmospheric Aerosols
Colin Gleason , Charles Harrington , Katie Schuff , Maria Battaglia , Robert Moore , Colin Turley , Michael Vineyard , Scott LaBrake

We are developing a research program in ion-beam analysis (IBA) of atmospheric aerosols at the Union College Ion-Beam Analysis Laboratory to study the transport, transformation, and effects of airborne pollution in Upstate New York. The simultaneous applications of the IBA techniques of particle-induced X-ray emission (PIXE), Rutherford back-scattering spectrometry (RBS), particle-induced gamma-ray emission (PIGE), and proton elastic scattering analysis (PESA) is a powerful tool for the study of airborne pollution because they are non-destructive and provide quantitative information on nearly all elements of the periodic table. PIXE is the main IBA technique because it is able to detect nearly all elements from Na to U with high sensitivities and low detection limits. The aerosol samples are collected with cascade impactors that allow for the study of particulate matter as a function of particle size and the samples are analyzed using proton beams with energies around 2 MeV from the Union College 1.1-MV Pelletron Accelerator. The emitted X-rays are measured using a silicon drift detector with a resolution of 136 eV. We will describe how the aerosol samples were collected, discuss the PIXE analysis, and present preliminary results.    [Preview Abstract]

 



EA.00044: Waiting Points and Bottlenecks in Nova and X-ray Burst Nucleosynthesis
Leah Goldberg

At Oak Ridge National Laboratory, we are investigating nucleosynthesis in nova explosions and X-ray bursts, specifically at ``waiting points'' and ``bottlenecks'' -- unusual phenomenon in which nuclei interrupt the sequence of thermonuclear reactions that form heavier elements from lighter ones, significantly affecting the final abundances and the energy generation rate in stellar explosions. Nuclei identified as waiting points or bottlenecks seem to play a more important role in explosions and need to be singled out for further investigation. Such points are defined by a series of acceptance and rejection tests in a simulation, Computational Infrastructure for Nuclear Astrophysics (CINA), in which a suite of codes visualizes nucleosynthesis over a specified time interval and allows us, for each nucleus, to consider eight surrounding nuclei in the Z=N plane based on possible reaction paths in the rp-process. After considering abundance, lifetime and reaction flux, reaction rate, and reaction Q-value, we accept or reject accordingly, and can then better ascertain the relationship between waiting points and bottlenecks and nuclear flow.    [Preview Abstract]

 



EA.00045: Program for Simulating Energy Spectra in Transfer Reaction Studies
S.A. Graves , R.L. Kozub , J.L. Wheeler , D.W. Bardayan

Studies of exotic nuclei with transfer reactions are important for nuclear structure studies and for many astrophysical applications such as understanding stellar explosions, the nuclear synthesis of lighter elements, and experimentally determining stellar reaction rates. However, the energy spectra from such reactions are sometimes counter intuitive and difficult to interpret. A FORTRAN program has been created to aid in visualizing the expected energy spectra of detected particles for any reaction having two particles in the exit channel. The user provides information about the reaction, the incident beam energy, and the angle of interest. The program produces a visual spectrum using nuclear databases, an existing kinematics code (RELKIN2), and the Xmgrace graphing software. The user is able to display multiple energy spectra so that the effect of various target components can be estimated. An example experimental setup and the output of this program will be presented.    [Preview Abstract]

 



EA.00046: Precision Target Mass Monitoring in the Antineutrino Detectors of the Daya Bay Reactor $\theta_{13}$ Experiment
Alexander Green

The Daya Bay Reactor Neutrino Experiment is designed to measure the neutrino mixing angle $\theta_{13}$ with a sensitivity of $sin^22\theta_{13} < 0.01$. The experiment consists of eight cylindrical antineutrino detectors filled with 20 tons of gadolinium-doped liquid scintillator as the target medium, surrounded by liquid scintillator and mineral oil. One of the dominant systematic errors of the measurement is the uncertainty of the detector target mass. To achieve the experimental sensitivity the detector target mass will be measured to better than 0.1\%. A network of sensors is being developed, which will be mounted in the antineutrino detectors to monitor the liquids inside the detector during data taking with high precision. This instrumentation consists of temperature sensors, inclinometers, capacitance liquid level sensors and ultrasonic liquid level sensors on an RS-485 network. We report on the design, fabrication and testing of this instrumentation system and its integration into the experiment's flow control system.    [Preview Abstract]

 



EA.00047: Assembly and Testing of the CUORE Calibration System
Ian Guinn

The Cryogenic Underground Observatory for Rare Events (CUORE) will search for neutrinoless double beta decay ($0\nu\beta\beta$) of $\rm ^{130}Te$. The observation of this decay would determine that neutrinos are of Majorana type, that is their own anti-particle. An array of natural $\rm Te0_{2}$ bolometers, operated at 10\,mK in order to minimize background radiation, will act as source and detector for this experiment. Since the extraction of the signal is based on energy information only, a precise calibration of the bolometers is extremely important. To calibrate the detectors, twelve strings with radioactive sources will be periodically lowered by motors through guide tubes into precise positions within the cryostat. The sources must be lowered carefully to avoid fricional heating and vibrations that may disrupt the calibration, so encoders, proximity sensors and load cells will be used to constantly monitor the status of each source as they are deployed. Furthermore, the source carriers have to be cooled to 4K to meet heat load requirements of the detector array, using a newly developed thermalization mechanism. This poster will describe testing of a prototype of the calibration system for CUORE and the development of the software control system.    [Preview Abstract]

 



EA.00048: Novel Method of Storing and Reconstructing Events at Fermilab E-906/SeaQuest Using a MySQL Database
Tyler Hague

Fermilab E-906/SeaQuest is a fixed target experiment at Fermi National Accelerator Laboratory. We are investigating the antiquark asymmetry in the nucleon sea. By examining the ratio of the Drell- Yan cross sections of proton-proton and proton-deuterium collisions we can determine the asymmetry ratio. An essential feature in the development of the analysis software is to update the event reconstruction to modern software tools. We are doing this in a unique way by doing a majority of the calculations within an SQL database. Using a MySQL database allows us to take advantage of off-the-shelf software without sacrificing ROOT compatibility and avoid network bottlenecks with server-side data selection. Using our raw data we create stubs, or partial tracks, at each station which are pieced together to create full tracks. Our reconstruction process uses dynamically created SQL statements to analyze the data. These SQL statements create tables that contain the final reconstructed tracks as well as intermediate values. This poster will explain the reconstruction process and how it is being implemented.    [Preview Abstract]

 



EA.00049: Study of the Helicity Dependent Parton Densities for the Electron-Ion Collider
Caitlin Harper

The Electron-Ion Collider (EIC) is currently being designed and one potential location could be Brookhaven National Laboratory through adding an electron beam to the Relativistic Heavy Ion Collider. One of the ultimate goals of the EIC is to look into the inner workings of quantum chromodynamics (QCD), the theory of strong interactions. The force that supplies the internal binding of strongly interacting particles is mediated by the exchange of gluons. Since gluons have colored charge they have the ability to interact among themselves, a unique feature of QCD. Upon completion, the EIC will allow us to study momentum and space-time distribution of gluons in nuclei. One specific key measurement at the EIC is to reveal the individual contributions of quarks and gluons to the spin of the proton at lower momentum fractions than have ever been measured at previous experiments. These factors are represented by the spin-dependent structure function g$_{1}$(x, Q$^{2})$, which covers a wide range in energy-scale, Q$^{2}$, and low momentum fractions, x. Further knowledge is attained through the study of deep inelastic scattering and their asymmetries.    [Preview Abstract]

 



EA.00050: Ion-Beam Analysis of Airborne Pollution
Charles Harrington , Colin Gleason , Katie Schuff , Maria Battaglia , Robert Moore , Colin Turley , Scott LaBrake , Michael Vineyard

An undergraduate laboratory research program in ion-beam analysis (IBA) of atmospheric aerosols is being developed to study pollution in the Capitol District and Adirondack Mountains of New York. The IBA techniques applied in this project include proton induced X-ray emission (PIXE), proton induced gamma-ray emission (PIGE), Rutherford backscattering (RBS), and proton elastic scattering analysis (PESA). These methods are well suited for studying air pollution because they are quick, non-destructive, require little to no sample preparation, and capable of investigating microscopic samples. While PIXE spectrometry is used to analyze most elements from silicon to uranium, the other techniques are being applied to measure some of the remaining elements and complement PIXE in the study of aerosols. The airborne particulate matter is collected using nine-stage cascade impactors that separate the particles according to size and the samples are bombarded with proton beams from the Union College 1.1-MV Pelletron Accelerator. The reaction products are measured with SDD X-ray, Ge gamma-ray, and Si surface barrier charged particle detectors. Here we report on the progress we have made on the PIGE, RBS, and PESA analysis of aerosol samples.    [Preview Abstract]

 



EA.00051: Neutron-Gamma Discrimination in Emerging Scintillators via Digital Signal Processing
T. Harrington , S. Lakshmi , P. Chowdhury

In this research, we report the results of neutron/$\gamma$- ray discrimination performed with two newly developed scintillator crystals provided by Radiation Monitoring Devices Inc. capable of both neutron and $\gamma$-ray detection, $Cs_{2} LiLaBr_{6}$ (CLLB) and $Cs_{2}LiYCl_{6}$ (CLYC). Neutron-gamma discrimination was performed by digitizing the pulse waveforms, from a PuBe source enclosed in paraffin, with a 1 GHz Lecroy Digital Oscilloscope. By exploiting the pulse shape differences between neutron and $\gamma$-ray waveforms in these new crystals, the neutron and $\gamma$-ray signals can be distinguished from one another. The Pulse Shape Discrimination method executed through custom software to discriminate between neutron and $\gamma$-ray waveforms will be discussed. The most recent results obtained using the CLYC and CLLB scintillator crystals coupled to a photomultiplier tube, which includes the optimization of the integration windows, will be presented and discussed.    [Preview Abstract]

 



EA.00052: Nuclear Resonance Fluorescence on $^{232}$Th
Alexander Hill

Nuclear resonance fluorescence (NRF) is a potent tool for isotope identification via $\gamma$-ray interrogation. NRF resonances at several energies were observed while irradiating $^{232}$Th with a 2.95 MeV linearly-polarized, quasi-monoenergetic $\gamma$-ray beam at the High Intensity Gamma Source (HI$\gamma$S) at Triangle Universities Nuclear Laboratory. In- and out-of-plane detectors recorded the emitted gamma rays. Statistical methods such as algorithmic background subtraction and signal variance analysis identified and isolated NRF peaks, revealing asymmetries in the emitted spatial distributions of $\gamma$-rays resulting from E1 and M1 transitions. In addition, a method of spectral unfolding for germanium gamma-ray detectors was developed to determine the energy distribution of the incident beam.    [Preview Abstract]

 



EA.00053: Betatron Tunes in the Proposed Medium-Energy Electron-Ion Collider at Jefferson Lab
Colin Jarvis , Balsa Terzic

The future of Jefferson Lab lies within the construction of a Medium-Energy Electron-Ion Collider (MEIC), which is currently in the proposal stage. In a synchrotron collider storage ring, the orbiting beams oscillate transversely in both the horizontal and vertical directions. The frequency of these oscillations is called the \textit{betatron} \textit{tune}. Depending on the design tune of the collider, non-linear beam-beam effects can cause rapid degradation of the beam quality, thus yielding poor luminosity, which is the figure of merit in the MEIC. The non-linear nature of the beam-beam effects poses a serious obstacle to the efficient analysis of potential design tunes. The goal of this research was to find an X and Y betatron tune, or \textit{working point}, which optimizes luminosity performance. Using code developed at Lawrence Berkeley National Lab, particle interactions were numerically simulated. Beginning with a previously known working point, systematic simulations were run to scan the adjacent tunespace. A subsequent working point was discovered that provides a 33 percent increase in theoretical peak luminosity over the current MEIC design.    [Preview Abstract]

 



EA.00054: CASCADE and PACE4 calculations for $\beta $ decay population of low-lying levels in 186Pt
En En Jiang , Cen Deng

Accurate information on the low-lying levels in the intermediate Pt nuclei, to serve as a basis for structural interpretation, is needed to study the transition from coexisting structures in the lighter Pt nuclei to $\gamma $ -soft structure in the heavier Pt nuclei. CASCADE and PACE4 reaction simulation programs were used to find suitable reactions for the production of unstable 186Au in different neutron channels that would allow the measurement of the energies and decay properties of low-lying levels in 186Pt, populated in the $\beta $-decay. The results of our calculations as well as a discussion on why we determined 175Lu (16O, 5n) to be the most efficient reaction, will be presented.    [Preview Abstract]

 



EA.00055: Neutron Elastic and Inelastic Scattering Cross Sections for Light and Heavy Nuclei in the 1$\sim$20 MeV region in Geant4
Michael Jones

Neutron interrogation of cargo containers provides a non-intrusive means of identifying Special Nuclear Materials (SNM) through their resulting spectra. However, before a Monte-Carlo analysis of an interrogation system can be performed, it is essential to validate and confirm the code's ability to correctly simulate and produce these spectra. Using Geant4, a simulation toolkit developed by CERN, the neutron elastic and inelastic scattering cross-sections for light and heavy nuclei in the 1$\sim$20 MeV region were calculated. Angle integrated cross-sections were obtained by fitting the angular distributions with Legendre polynomial expansions. The results of these calculations were compared with corresponding experimental data. The analysis showed that the simulations consistently underestimated neutron resulting in large discrepancies in the angle integrated cross-sections for heavier nuclei.    [Preview Abstract]

 



EA.00056: Neutron Detector Shielding Using Boron and Water
Frederick Jung , Andreas Best , Ani Aprahamian , Michael Wiescher

There has always been a need to develop better shielding for particle detectors from background radiation. With the development of DUSEL (Deep Underground Science and Engineering Laboratory at Homestake), new opportunities exist to make measurements away from the surface cosmic radiation. Doing measurements underground, coupled with better shielding, allows measurements of reactions that are too weak to observe otherwise. Underground, we can take advantage of thousands of meters of rock to shield detectors from cosmic background radiation. Even this rock can be insufficient, as a naturally occurring radioisotopes found in the rock can yield many kinds of radiation, such as gamma rays, beta rays, alpha particles, neutrons, and other fission products. We are designing and testing a shield made for our proportional neutron detectors made of boron and water. Water is used to slow down, or thermalize, the neutrons. Boron is in turn used to capture the incoming neutrons, due to its large neutron capture cross section. This shield was tested and the data has been analyzed, showing that we can achieve a factor of 63 reduction in the number of neutrons detected. We will also scale down this design so that it can provide background protection to detectors in the Nuclear Structure Laboratory at the University of Notre Dame.    [Preview Abstract]

 



EA.00057: A Statistical Model of the Pure Glueball and Glueball Hybrids
Meghann Kennedy , Tyler Matossian

Glueballs are predicted by QCD and have been sought for years in many experiments. Although there are several candidates, glueballs are difficult to identify because they can decay into quark-antiquark pairs, mesons or other hybrid states. In this study we used the statistical model of Y-J. Zhang et al. to represent the pure glueball as a Fock state expansion in terms of gluons. Assuming detailed balance between states, we calculated a probability of 45.6\% for the two-gluon state and 30.4\% for the three-gluon state; the probability of subsequent states decreased with each additional gluon. The average number of gluons in a glueball was calculated to be 2.91. We represented the hybrid glueball by adding quark-antiquark pairs to the Fock state expansion. The probabilities of hybrid glueball states were calculated to explore state mixing and predict the relative probabilities with which each state can be observed in experiment.    [Preview Abstract]

 



EA.00058: Quasielastic Neutron-Induced Deuteron Breakup.
Katrina Koehler , Peter Kroening , Jonathon Slye , Jared Turkewitz , Sho Uemura , Vlad Henzl , June Matthews , Steve Wender , Mark Yuly

An experiment to measure the quasielastic d(n,np)n scattering cross-section was conducted at the Los Alamos Neutron Science Center (LANSCE) at intermediate incident neutron energies, ranging up to 800 MeV. Scattered protons from deuteron breakup travel through a magnetic spectrometer on beam right, consisting of a thin $\Delta $E scintillator, three drift chambers, two permanent magnets, and two thin E scintillators. An array of nine two-meter high plastic scintillators detects scattered neutrons on beam left. Analysis of the data from this experiment is underway to determine the scattered angles and energies of the particles, and subsequently the scattering cross-section for the n-d breakup reaction.    [Preview Abstract]

 



EA.00059: Maximizing Ion Collider Luminosity Through Genetic Optimization of Beam Tunes
Matthew Kramer

In designing a particle collider, one goal is to achieve the maximum feasible luminosity, a measure of the rate of collision events. Luminosity depends, in part, on a set of parameters known as the betatron tune working points (oscillation frequencies) of the beam. The relationship is complicated and nonlinear, making optimization extremely difficult. Researchers have long sought viable algorithms for solving this problem. Here, a massively parallel genetic algorithm was developed and used to locate high-luminosity working points for the proposed Medium Energy Ion Collider currently being designed at Jefferson Lab. The algorithm made use of the BeamBeam3D package to perform beam-beam simulations and to then calculate the luminosity of each working point. It was found that after five or more generations, the algorithm successfully located working points with luminosities exceeding the proposed design luminosity of the collider. These results demonstrate that such algorithms provide a feasible solution to this type of problem. Owing to the parallel evaluation of working points, a large subset of tune space can be covered relatively quickly (one or two days). It is hoped that such methods may prove useful for various other difficult optimization problems in accelerator design.    [Preview Abstract]

 



EA.00060: Polarization of Target in Crystal Ball Calorimeter
Jennifer Kuczynski , William Briscoe , Andreas Thomas

A pion photo-production experiment is being conducted at MAMI-lab in Mainz, Germany. In Mainz I was working at the Mainz Microtron (MAMI) using a polarized tagged photon beam, a transversely polarized proton target, and the Crystal Ball calorimeter. The Crystal Ball can measure energy, position energy and timing at many angles. A butanol polarized target was used in the May/June run of the Crystal Ball experiment. Finding an accurate relaxation time for the polarization will be useful in determining a proper time for each experimental run.    [Preview Abstract]

 



EA.00061: Using Fiber Optics to Measure Carrier Drift Velocity of Germanium at 40mK
Albert Lam

The Cryogenic Dark Matter Search (CDMS) uses ultrapure germanium detectors at milliKelvin temperatures to attempt to directly detect weakly interacting massive particles (WIMPs), a candidate for dark matter. When some particle interacts with the crystal structure, ionization and phonon signals are produced. Each particle interaction gives off a unique ratio of ionization signal to phonon signal. In this way, background noise can be separated from events that may involve WIMPs. Current germanium detectors are about the size of a hockey puck. If detectors can be made larger, there would be a greater probability of having a WIMP interaction. To make larger detectors, we need to better understand carrier transport processes in the germanium detectors. So, we measured the carrier drift velocity at 40milliKelvin, the temperature at which detectors operate. The carrier drift velocity gives us insight into how much impurity is present in the germanium detectors. We made this measurement using a fiber optics line. The fiber optics line allowed us to carry light from a 780nm laser diode at room temperature, into our dilution refrigerator and onto a germanium detector at 40milliKelvin. A laser diode allowed us to create electron-hole pairs on the surface of a germanium detector in a much more precise way than a radiation source.    [Preview Abstract]

 



EA.00062: Hot Filament Alignment System
Edward Lamere

The ``a'' Correlation in Neutron Decay (aCORN) collaboration seeks to measure the electron-antineutrino correlation in free neutron decay to within 1{\%} relative uncertainty as a test of the Standard Model. To accomplish this, two regions of the phase space of the decay must be isolated. The correlation parameter, ``little a,'' is proportional to the counting asymmetry between these two groups. Before the final measurement can be performed, an in-situ test of the alignment of the magnetic field and the experimental axis, set by a series of tungsten collimators, must be checked. Any misalignment would introduce an asymmetry in the experiment, resulting in an inaccurate ``little a'' measurement. To test the alignment a filament can be quickly inserted into the aCORN vacuum tube, which produces low energy electrons when heated. These electrons will travel nearly straight along the magnetic field lines due to their minimal cyclotron radius. A misalignment of the field can be determined from the relative currents detected on the final, segmented collimator. A description of the preliminary work on an in-situ alignment system will be presented.    [Preview Abstract]

 



EA.00063: The Similarity Renormalization Group with Novel Generators
Weishi Li

The Similarity Renormalization Group (SRG) uses a series of unitary transformations to decouple high-energy and low-energy physics. Because of the properties of unitary transformations, the SRG automatically preserves physical observables while decoupling allows the truncation of the Hamiltonian, improving convergence. With the relative kinetic energy ($T_{\rm rel}$) as the generator, the SRG has been applied successfully for several years to calculate nuclear structure. However, only a few generators have been explored. Different generators relate to different evolving patterns and parameters. Here some new alternatives, such as an exponential form of $T_{\rm rel}$, are evaluated for the degree of decoupling and improvements in computing speed.    [Preview Abstract]

 



EA.00064: Improved Interlock System at the Nuclear Structure Lab at Univ. of Notre Dame
Xao Lor , Shelly Lesher , Ed Stech

The current interlock system at the Nuclear Structure Lab (NSL) at the University of Notre Dame requires multiple procedures to be performed in order to start up one of the three accelerators. New features and equipment will be added to the current interlock system to allow access into the experimental rooms safely. This change is necessary because the planned addition of experimental equipment will allow beams from two accelerators to enter the same target hall. In order to minimize the impact of one experiment on another, access will be determined by active monitoring of the radiation levels in the rooms instead of the possibility of accelerated beam being present. New equipment planned to be used in the laboratory are personal dosimeter badges, with a monitor reader for a pass-by data exchange and monitor screens to display live radiation levels and access levels in all of the experimental rooms. This poster will present this procedure and explain how personnel can access the NSL rooms safely while the ion beams are on.    [Preview Abstract]

 



EA.00065: Production and Quality Tests of Carbon Strip Targets for RHIC Polarimetery
William Lynn

Spin physics at BNL involves the study of polarized proton-proton collisions in order to better understand proton spin structure. The RHIC accelerator complex is capable of producing a longitudinal or transversely polarized proton beam with a maximum polarization of 70\% and up to a beam energy of 250 GeV. Since research depends heavily on the degree of polarization of the proton beam, it is necessary to check the polarization of the beam after it has left its source by using a polarimeter. There are two polarimeters at RHIC, the Hydrogen-Jet and proton-Carbon (pC) polarimeters. The pC polarimeters measure the polarization of the protons by colliding the beam with a carbon strip target and then measuring the angle of deflection. The targets used in pC polarimeters are manufactured at BNL through an evaporation technique and must have a width of less than 10 $\mu$m. After production, quality checks must be made to ensure that the carbon targets are suitable for use. This poster will focus on the production and quality control of the targets to be used in pC polarimeters.    [Preview Abstract]

 



EA.00066: Probing Micro Black Holes and Extra Dimensions through IceCube
Sultan Malik

If extra space dimensions and low-scale gravity exist, Microscopic Black Holes (MBHs) will be produced in collisions of elementary particles. Ultrahigh-energy cosmic neutrinos, also known as GZK neutrinos, provide a promising window on this phenomenon. For GZK neutrinos above $\sim $10$^{7}$GeV, the MBH production cross section in neutrino-nucleon interactions exceeds the standard model cross section by two or more orders of magnitude increasing the chances of detection by neutrino observatories. The IceCube neutrino observatory, buried 1.4 km under the Antarctic ice near the South Pole, was used to probe production of MBHs in this analysis. One month data from the IceCube detector was searched for events that could be possible MBH events. The expected number of events was also calculated theoretically for both the Standard Model cross section and the MBH model cross section using a standard GZK flux prediction. No significant MBH events were found in the data analysis which is consistent with the low expected number of MBH events. Detecting MBH directly requires large amount of observable data, and so is not an effective method for probing MBHs. Further study is required to come up with indirect ways of detecting MBH production using IceCube.    [Preview Abstract]

 



EA.00067: Neutron Detection Improvements for Measurement of Neutron Lifetime
Gregory Manus , Chen-Yu Liu , Daniel Salvat , Christopher Cude , Aaron Hanson , Sonya Sawtelle

Ultra Cold Neutrons (UCN) have energies low enough to be confined in material and magnetic traps, yet it makes transmission into typical neutron detectors a nontrivial task. The neutron lifetime experiment at LANL may require improvements to a standard ionization chamber detector or an entirely different approach to UCN detection [1]. We compare Si and Zr ionization chamber windows to their Al counterparts. Si's smooth surface and uniform bulk density reduces the total elastic scattering cross-section. Zr's mechanical strength enables thinner, more transparent detector windows than Al. Also, various geometries of electrode grid planes are simulated in Garfield and built. Furthermore, to minimize time and spectrum dependent systematic errors of collection efficiency, we bypass transporting the UCN from trap to detector by detecting UCN directly in the trap. Here we empty BF3 and Ar into the trap where UCN capture in B releases Li and $\alpha $ particles detected by their ionization of Ar. The B capture also emits a gamma which can be detected. Details and progress will be presented at the conference. \\[4pt] [1] Nucl Instrum Meth A 599 (2009) 82-92    [Preview Abstract]

 



EA.00068: New Trigger Logic for the STAR Forward Meson Spectrometer
John Calvin Martinez

The Forward Meson Spectrometer (FMS) is an electromagnetic calorimeter in the STAR Experiment at RHIC that covers the pseudorapidity region 2.5 $<$ eta $<$ 4 and full azimuth. One of the goals of the FMS is to separate two possible causes of large, previously observed proton transverse single-spin asymmetries, the Sivers effect and the Collins effect. To meet this goal, it will be valuable for the FMS to trigger more efficiently on eta mesons and jet-like events than it does at present. In order to increase the trigger efficiency for non-localized events, like jets and eta decays, a new trigger algorithm has been developed that includes a system of eight overlapping jet-patches, each covering an approximate area of 1.5 x 1.5 in azimuth-pseudorapidity space. The new trigger logic and the expected rates for 200 and 500 GeV p+p collisions will be presented.    [Preview Abstract]

 



EA.00069: Magnet Design and Simulation for Neutron Interferometry
Robert Milburn , Chris Crawford , Elise Martin

The study of neutron interferometry highlights some of the essential components of quantum mechanics allowing us to study the wave-like nature of the neutron. The spin of polarized monochromatic neutrons in an interferometer can be flipped by passing through a static B-field perpendicular to the holding field. Constraints on such a magnet are that the field must be constant within a cylindrical volume, but zero everywhere outside the coil. A double cosine theta coil meets the needs of this particular device. The design, simulation, and plans for construction of this magnet will be presented.    [Preview Abstract]

 



EA.00070: Determining the Light Antiquark Asymmetry in the Nucleon Sea with FNAL E-906/SeaQuest
Benjamin Miller

SeaQuest will use the Drell-Yan process to improve our knowledge of the structure of the nucleon. This experiment will determine the ratio of anti-down to anti-up quarks to larger Bjorken-x than was attained by earlier experiments. SeaQuest's predecessor, Fermilab E-866/NuSea extracted the ratio to x $\approx$ .2 with reasonable precision. SeaQuest will extend the measurements of light antiquark asymmetry to x $\approx$ 0.45. SeaQuest will use the Fermilab 120 GeV/c Main Injector to collide protons with targets of liquid hydrogen, liquid deuterium and, for other measurements, solid nuclear targets. The detector under construction is a two-magnet, focusing spectrometer with four detector stations, similar to the E866/NuSea spectrometer. By comparing the Drell-Yan di-muon cross sections for both proton- proton and proton-deuterium collisions, we can extract $\bar {d}$/$\bar{u}$ for the proton and better understand the properties of the sea of the nucleon.    [Preview Abstract]

 



EA.00071: High Energy Pion Photoproduction from Nucleons in the Giessen Bolzmann-Uehling-Uhlenbeck Model
Prajwal Mohanmurthy

For long, the transitions between perturbative and nonperturbative regimes of QCD have been of interest in nuclear physics. One of the methods used to study these transitions is to look for the onset of predictive QCD laws such as the quark counting rule. Measuring the differential cross section of certain exclusive reactions (such as pion photo production) has been one of the prime methods of investigating quark counting rules. The CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Jefferson Lab (JLAB) has been used to measure the cross sections of pion photo production reactions. These measurements can be used to better understand the scaling laws. Although the cross-section does show scaling behavior, the onset of scaling is at unusually low energies and an unexplained sharp drop in the cross-section is observed just before the onset of scaling. There is a lack of theoretical calculations of pion photo production cross-section at these energies. The model known as the Giessen Boltzmann-Uehling-Uhlenback (GiBUU) model has been used to calculate the pion photo-production cross-section and it was compared with the CLAS measurements. The preliminary results shall be presented.    [Preview Abstract]

 



EA.00072: Silicon-Strip Detectors for the Array for Nuclear Astrophysics Studies with Exotic Nuclei
L.L. Mondello , J.C. Blackmon , L. Linhardt , M. Matos , E.F. Zganjar , E. Johnson , G. Rogachev , I. Wiedenhover

The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN) is a charged-particle detector array that is targeted towards reaction studies with radioactive ion beams at FSU and the NSCL, primarily to help improve understanding of the nuclear reactions important in stellar explosions. New resistive, double-sided silicon-strip detectors were designed and constructed for ANASEN that aim for precise position and energy resolution using a modest number of channels. The first 12 (of 40) detectors for ANASEN were tested at LSU with a 241Am alpha source to characterize the position resolution, energy resolution, and effective length for each detector element, as well as the optimum operating voltage. A custom 72-channel preamplifier unit has also been constructed for silicon-strip detectors, and the performance of the preamplifier as a function of input series resistance was also studied. We will present the results of the source tests and plans for commissioning with ion beams.    [Preview Abstract]

 



EA.00073: Simulating the Neutron Detection Efficiency of the CLAS12 Detector
M. Moog , G.P. Gilfoyle , J. Carbonneau

We have studied the expected performance of the CLAS12 detector that will be built at Jefferson Lab as part of the 12-GeV Upgrade. The Upgrade hopes to further our understanding of the internal structure of nucleons and nuclei by studying properties such as form factors and generalized parton distributions. The initial round of experiments for the Upgrade include ones requiring neutron detection and we are studying the neutron detection efficiency (NDE) in preparation for such experiments. A precise knowledge of the NDE is required to keep systematic uncertainty low. We studied the CLAS12 performance by generating the four-momenta of an electron and neutron after a relativistic, elastic collision and passing this information into the GEANT4-based program gemc. This code uses the four-momenta of these particles and simulates their interaction with the CLAS12 components. Events were reconstructed with the program Socrat. By comparing the number of measured elastically-scattered, electron-neutron coincidences to the number of elastic electrons detected in the simulation we extracted the NDE of the time-of-flight (TOF) scintillators. In previous work we studied one set of TOF panels and have now extended this work to include the full array of TOF scintillators in the simulation and expanded the neutron momentum range.    [Preview Abstract]

 



EA.00074: Spectroscopy of Heavy Nuclei with GAMMASPHERE
K. Moran , S. Hota , S. Lakshmi , P. Chowdhury

We report on analysis of data from a recent experiment carried out using the ATLAS heavy-ion accelerator facility at Argonne National Laboratory. A beam of \hspace{2pt}$^{208}$Pb was incident on a $^{244}$Pu target evaporated on a $^{197}$Au backing. The target and projectile nuclei were mutually excited to high-energy states via inelastic collisions. The GAMMASPHERE detector array, made up of 108 Compton-suppressed germanium detectors positioned in a spherical geometry around the target, was used to detect the resulting gamma radiation as the nuclei decayed to ground state. The data from the experiment was then sorted into a three-dimensional $\gamma$-$\gamma$-$\gamma$ ``cube,'' which was analyzed using gating techniques in Radware software to investigate the decay structure of the excited nuclei produced by the experiment. A two-dimensional ``matrix'' was also created using an early-delayed technique, allowing for short-lived isomers produced in-beam to be observed. This data was analyzed using time gates to measure half-lives of observable isomers. Results will be presented and discussed.    [Preview Abstract]

 



EA.00075: The influence of eccentricity fluctuations on the extraction of the QGP shear viscosity from elliptic flow data
J. Scott Moreland , Ulrich Heinz , Huichao Song

In a recent paper [Phys. Rev. C 80 (2009) 061901] we showed that systematic studies of the impact parameter dependence of the eccentricity-scaled elliptic flow $v_2/\epsilon$ can distinguish between different models for the calculation of the initial source eccentricity. These calculations were done with viscous relativistic hydrodynamics in 2+1 space-time dimensions, assuming longitudinal boost-invariance and using the optical versions of the Glauber and fKLN (Color Glass Condensate) models to describe the initial energy density profiles. Here we report on the results on a follow-up study that includes the effects of event-by-event fluctuations in the shape and orientation of the reaction zone that defines the initial fireball density. We explore the effects of eccentricity fluctuations on the collision centrality dependence of the eccentricity-scaled elliptic flow and compare the results with experimentally observed trends in Au+Au collisions at the Relativistic Heavy Ion Collider.    [Preview Abstract]

 



EA.00076: LED Monitoring System of the Phenix Muon Piston Calorimeter
Steven Motschwiller

The Muon Piston Calorimeter in the PHENIX experiment at RHIC has a monitoring system consisting of LEDs and PIN diodes to calibrate out the time dependent changes to the detector. The LEDs track the temperature and radiation-damage changes to the response of the MPC, while the absolute calibration can be done using $\pi^{0}$ decays. To execute this, LEDs flash light through the PbWO4 crystal to the Avalanche Photo Diodes The MPC is made up of 416 independent electromagnetic calorimeter towers. By using the LEDs we can correct for changes in the gains of each tower in the MPC, on a run by run basis. Because the LED value only gives a relative measurement of the gain over time, this method of calibration can only be used in conjunction with absolute calibrations provided by $\pi^{0}$ decays or by minimum ionizing peaks . This work will be used to make a final measurement on Transverse energy at $\sqrt{s_{NN}}$ = 200 GV in Au+Au collisions.    [Preview Abstract]

 



EA.00077: Simulation of the CLAS12 Forward Electromagnetic Calorimeter
C.J. Musalo , G.P. Gilfoyle , J. Carbonneau

The primary mission of Jefferson Lab (JLab) is to reveal the quark and gluon structure of nucleons and nuclei and to deepen our understanding of matter and quark confinement. At JLab there is a need for high-performance computing for data analysis and simulations. The precision of many future experiments will be limited by systematic uncertainties and not statistical ones; making accurate simulations vital. A physics-based simulation of a new detector (CLAS12) is currently being developed called gemc. This new program uses the package Geant4 to calculate the interactions of particles with matter in the components of CLAS12. We have added the electromagnetic calorimeter (EC) detector to the gemc simulation. The EC is a sampling electromagnetic calorimeter made up of alternating layers of lead and plastic scintillator used to detect electrons, photons, and neutrons. The mathematical model of the EC geometry was streamlined to make the code more robust. This geometry is stored in a mysql database on a server at JLab and it was modified using Perl scripts. The new geometry was tested by sending straight tracks (no magnetic field) through the edges of specific layers using the geantino, a Geant4 virtual particle that does not interact with materials. Work supported by US Department of Energy contract DE-FG02-96ER40980.    [Preview Abstract]

 



EA.00078: Testing the Large-area multi-Institutional Scintillator Array (LISA) Neutron Detector
T.B. Nagi , K.M. Rethman , K.A. Purtell , A.J. Haagsma , C. DeRoo , M. Jacobson , S. Kuhn , A.R. Peters , M. Ndong , S.A. Stewart , Z. Torstrick , R. Anthony , H. Chen , A. Howe , N.S. Badger , M.D. Miller , B.J. Foster , L.C. Rice , C. Vest , A.B. Aulie , A. Grovom , L. Elliot , P. Kasavan

The 144 detector modules comprising the Large-area multi-Institutional Scintillator Array (LISA) neutron detector were tested at each of the nine primarily undergraduate institutions. Each module is a 200 cm by 10 cm by 10 cm bar of EJ-200 organic plastic scintillator a with a photomultiplier tube mounted on each end. We used cosmic rays both to ensure that each module was light tight as well as to characterize position and time resolution. In addition, we measured each module's light attenuation using gamma sources. Results will be presented.    [Preview Abstract]

 



EA.00079: A MIP-based Energy Calibration of the STAR Endcap Electromagnetic Calorimeter for 2009
Zachary Nault

The Endcap Electromagnetic Calorimeter (EEMC) is an integral part of the STAR detector at RHIC. The EEMC is used in detecting forward particles from polarized proton interactions, which aid in understanding the spin structure of the proton. In order to properly use the data collected, the energy and position measurements in the EEMC need to be well-known. To accomplish this, a calibration of the EEMC was done using minimum ionizing particles (MIPs) for the 2009 run. A description of this method and the current status of the energy calibration will be presented.    [Preview Abstract]

 



EA.00080: A Database for the Low Background Facility at Lawrence Berkeley National Laboratory
Khang Nguyen , James Loach

The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory (LBNL) has been serving the worldwide research community since 1962, providing radiopurity measurements of a huge number of different materials. The 100,000 assays that have been performed have contributed to the success of many important experiments, such as SNO and KamLAND, but have mostly remained unavailable to the wider community. A project undertaken by the Neutrino Astrophysics Group at LBNL aims to make the data accessible by creating a comprehensive database of assay results with an accompanying web application. This poster outlines the project.    [Preview Abstract]

 



EA.00081: Search for angular anisotropies in neutron emissions of fragmentation reactions with secondary beams
Sam Novario , Greg Christian , Jenna Smith , Michael Thoennessen

Projectile fragments from the breakup of a secondary beam of $^{29}$Na were measured in coincidence with neutrons expelled in the reaction. A 140 MeV/u $^{48}$Ca beam from the Coupled Cyclotron Facility at Michigan State University was used to produce the secondary $^{29}$Na beam at an energy of 102 MeV/u. This beam impinged on a 987 mg/cm$^{2}$ $^{9}$Be target and the outgoing fragments were deflected by a superconducting 4 T large-gap dipole magnet and analyzed with a set of energy-loss, timing and position sensitive detectors while the outgoing neutrons were measured with the Modular Neutron Array MoNA. The central purpose of the experiment was to study individual neutron unbound resonances in the fragments. In addition, the analysis of the continuum distributions offers the opportunity to investigate reaction dynamical effects. For example, the neutron multiplicity can yield information about the distribution of the initially produced fragments. Also, the angular distributions of the emitted neutrons relative to the fragments may contain information about the fragmentation process. We searched for anisotropies in these angular distributions for several isotopes from Z = 5 through Z = 10 fragments. Initial results will be presented.    [Preview Abstract]

 



EA.00082: Discovery of Isotopes
A. Nystrom , A. Parker , M. Thoennessen

To date, no comprehensive study has been undertaken regarding the initial detection and identification of isotopes. At NSCL, a project has been initiated to catalog and report the initial observation of every isotope. The conditions characterizing the successful discovery of an isotope include a clear and unambiguous mass and element identification through decay curves, mass spectroscopy, $\gamma$-ray spectra, and/or relationships to other isotopes, as well as the publication of such findings in an adjudicated journal. Prior to this work, research on the discovery of isotopes for approximately sixty-five different elements had already been performed within the bounds of this project$^{4}$. Here we present the documentation for nine new elements: rubidium, strontium, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, and rhodium. 31 rubidium, 35 strontium, 34 yttrium, 35 zirconium, 34 niobium, 35 molybdenum, 33 technetium, 38 ruthenium, and 38 rhodium isotopes have been discovered so far. The year and author of each initial publication are discussed, along with the location and methods of production and identification. A summary and overview of all $\sim$2000 isotopes documented so far as a function of discovery year, method and place will also be presented.    [Preview Abstract]

 



EA.00083: The Ursinus College Liquid Hydrogen Target
Jessica Palardy , Nicholas Ferrante , Lewis Riley , Remco Zegers

The Ursinus College Liquid Hydrogen Target has been constructed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University, for the purpose of eliminating unwanted gamma-rays from carbon in polyethylene or deuterated polyethylene targets that are commonly used in experiments requiring thick proton targets. Existing geant4 simulations of the Segmented Germanium Array (SeGA) and the CAESium iodide ARray (CAESAR) have been modified to incorporate the liquid hydrogen target. The impact of the target on gamma-ray detection efficiencies and the use of the simulations to plan experiments with the target are discussed.    [Preview Abstract]

 



EA.00084: Motor Controls for the NIFFTE Time Projection Chamber Positioning Stand
Daniel Pamplin , Nathan Pickle

The next generation nuclear power plants will be more efficient and produce smaller amounts of radioactive waste. Design of these new reactors is limited partially by the lack of precise neutron induced fission cross sections at certain incident neutron energies of several isotopes. In order to reduce the uncertainty of the cross sections to less than 1 percent, a Time Projection Chamber (TPC) was built by the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration. These improvements in precision will be possible due to the TPC's ability for a full 3-D reconstruction of the fission fragment tracks. The NIFFTE TPC will be installed at Los Alamos National Lab's LANSCE facility. Thin targets will be mounted in the center of the TPC in a pressurized hydrogen gas chamber so that both hemispheres of the reaction will be covered. In this work we will discuss the control of the stepper motors that drive the positioning table of the TPC, which has all of its readout electronics attached, to be lined up with the beam. This includes both the controlling software and its graphical interface to the MIDAS online data acquisition system.    [Preview Abstract]

 



EA.00085: Using C++ and SRIM to improve energy resolution using the STARS/LiBerACE arrays
Benjamin Pauerstein , Jack Shaw , Danyi Chen , Tim Ross , Richard Hughes , Con Beausang

An experiment was conducted at LBNL using the STARS/LiBerACE arrays in which a 25 MeV proton beam was incident on 154, 156, and 158Gd targets to study nuclei around the N=90 shape-change region. STARS uses a delta-E and E silicon detector telescope to identify the type and direction of emitted light, charged particles. Each CD shaped detector is segmented into 24 rings. The data sorting program approximates the angle at which a charged particle was scattered by choosing the angle required to hit the middle of the ring struck in the delta-E detector. This angle is then used to calculate energy losses in the dead layers, and hence the particle's total energy. This method is non-optimal as not all of the particles hit the detector at these angles, and improving the angular resolution should improve the energy resolution. SRIM was used to calculate particle energy loss per unit distance travelled in various materials; a C++ program was then written to obtain detailed energy loss calculations for particles as a function of angle and particle energy measured in the E detector. Preliminary results will be presented. This work is supported by the DOE under grants DE-FG02-52NA26206 and DE-FG02-05ER41379.    [Preview Abstract]

 



EA.00086: Sensitivity Study Investigating the Effect of Nuclear Masses on R-process Abundances
Nancy Paul , Samuel Brett , Ani Aprahamian

Nuclear masses play a critical role in r-process nucleosynthesis, which, though poorly understood, is thought to account for more than 50 percent of the abundances of elements heavier than iron. Using the NGAM nucleosynthesis simulation code and the FRDM mass model, we performed a sensitivity study to identify nuclei whose masses have the greatest impact on the entire r-process abundance distribution. We adjusted the individual FRDM masses by 25 percent and evaluated the overall impact compared to baseline abundances generated from the FRDM masses. We determined the effects of these adjustments by considering both the maximum change and the RMS change in final r-process abundances. We identified several critical nuclei that would be most important to measure in future experiments at radioactive ion-beam facilities although not all nuclei are experimentally accessible at the present time.    [Preview Abstract]

 



EA.00087: BECOLA Beam Line Construction and Laser System
Eowyn Pedicini , Kei Minamisono , Brad Barquest , Georg Bollen , Andrew Klose , Paul Mantica , Dave Morrissey , Ryan Ringle , Stefan Schwarz , Sophia Vinnikova

The BECOLA (BEam COoler and LAser spectroscopy) facility is being installed at NSCL for experiments on radioactive nuclides.\footnote{K. Minamisono \textit{et al}, Proc. Inst. Nucl. Theory \textbf{16}, 180 (2009).} Low energy ion beams will be cooled/bunched in an RFQ ion trap and then extracted to a max of 60 kV. The ion beam will be neutralized through a charge exchange cell (CEC), and remaining ions will be removed by a deflector and collected in a Faraday cup. Collinear laser spectroscopy will be used to measure the atomic hyperfine structure, and nuclear properties will be extracted. The assembly, vacuum testing, and optical alignment of the CEC have been completed and the ion deflector and Faraday cup were also assembled. Stabilization of the Ti:sapphire laser to be used for spectroscopy is achieved through a feedback loop using a precision wavelength meter that is calibrated by a stabilized He-Ne laser. Coupling the He-Ne laser into a single-mode optical fiber was optimized for stable operation of the feedback loop. Finally, a wall chart of nuclear moments was prepared to view trends in $\mu$ and Q for nuclear ground states for planning future measurements.    [Preview Abstract]

 



EA.00088: Filtering, Processing, and Analysis of aCORN Project Data
Andrew Portuguese

The aCORN collaboration seeks to measure the electron-antineutrino correlation in free neutron beta decay characterized by the dimensionless parameter ``\textit{little a}'' within a 1{\%} relative uncertainty. Cold neutrons decay in the apparatus, and in-coincidence proton and electron detection allows the measurement of the beta electron energy as well as the proton time-of-flight (TOF). The configuration of the apparatus permits coincidence detection in two distinct decay cases, distinguished by the proton TOF, and the experimental asymmetry of these cases enables precise determination of $a$. Since many decays must be used, a data acquisition system with high throughput is necessary to acquire, filter, process, and store all gathered coincidence data in a usable form. aCORN utilizes a Pixie-16 data acquisition system to digitize signals in a 12-bit ADC at a rate of up to 100 MHz. Digitized detector events are time sorted, coincidences are identified, and each fully absorbed electron energy event is stored with its corresponding proton TOF. The analysis code can be adapted to store any other detected data. The principles of the aCORN data handling system will be discussed in this presentation.    [Preview Abstract]

 



EA.00089: First Nuclear Self-Absorption Experiment at HI$\gamma$S Relevant to Astrophysics
S. Pratt , G. Rusev , E. Kwan , R. Raut , A.P. Tonchev , J.H. Kelley , R. Schwengner

In supernovae explosion, about 35 nuclei cannot be produced by $r$ or $s$ processes. These co-called $p$ nuclei can be created by photodisintegration reactions only. Furthermore, network calculations underpredict the abundances of the $p$ nuclei which require more precise measurements of the photo-induced reactions. The accuracy of those measurements rely on the uncertainty of the width of the levels in $^{11}$B used as a calibration standard. These are currently known with a relative uncertainty not better than 5\%. We report the results for the width of the levels at $7.285$ and $8.920$ MeV in $^{11}$B from the first nuclear self-absorption experiment at the High Intensity $\gamma$-Ray Source Facility at Triangle Universities Nuclear Laboratory using monoenergetic photon beams.    [Preview Abstract]

 



EA.00090: Performance comparison of MoNA and LISA neutron detectors
Kimberly Purtell , Kaitlynne Rethman , Autumn Haagsma , Joseph Finck , Jenna Smith , Jesse Snyder

In 2002 eight primarily undergraduate institutions constructed and tested the Modular Neutron Array (MoNA) which has been used to detect high energy neutrons at the National Superconducting Cyclotron Laboratory (NSCL). Nine institutions have now designed, constructed and tested the Large-area multi-Institutional Scintillator Array (LISA) neutron detector which will be used at the NSCL and the future Facility for Rare Isotope Beams (FRIB). Both detectors are comprised of 144 detector modules. Each module is a 200 x 10 x 10 cm$^3$ bar organic plastic scintillator with a photomultiplier tube mounted on each end. Using cosmic rays and a gamma source, we compared the performance of MoNA and LISA by using the same electronics to check light attenuation, position resolution, rise times, and cosmic ray peak widths. Results will be presented.    [Preview Abstract]

 



EA.00091: Improving Sr Radioactive Ion Beams at HRIBF
Fatima Rafique , Hubert Carter , Carola Jost , Ronald Goans

The research conducted at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL) utilizes high quality radioactive ion beams (RIBs) to explore the structure of nuclei. This research reviews chemical techniques to improve the intensity and purity of these radioactive ion beams, in particular strontium (Sr) ion beams. A past experiment on $^{92}$Sr showed that the intensity of the Rb contamination was approximately half of the Sr intensity. K$o$ster \textit{et al}. (2008) reported that RbF molecules do not ionize in the ion source, whereas the SrF molecules do. Taking this into account, the data from an old experiment which introduced SF$_{6}$ to the target/ion source was reanalyzed. The yield for $^{93}$SrF was found to be about 4.55 x 10$^{6}$ ions/sec/$\mu $A, while for $^{93}$RbF it was less than 0.2{\%} of $^{93}$SrF. These results are encouraging; therefore, a detailed optimizing experiment using CF$_{4}$ gas is expected to be carried out soon and the results will be presented in the poster.    [Preview Abstract]

 



EA.00092: Mass Constraints on Fourth Generation of Standard Model Fermions
Enrique Ramirez-Homs , Leo Bellantoni , Jens Erler

Current experimental bounds on fourth-generation, standard model fermion masses are revisited. Assuming a fourth generation, we cast uniformly distributed masses for four fermions and determine a probability density function based on consistency with the electroweak oblique parameters, S, T, and U, convoluting over Higgs masses. Recent TeVatron combination limit on Mh in the fourth generation scenario is used and a probability density function for the four fermions is obtained.    [Preview Abstract]

 



EA.00093: Construction of the Large-area multi-Institutional Scintillator Array (LISA) Neutron Detector
Kaitlynne Rethman , Kimberly Purtell , Autumn Haagsma , Casey DeRoo , Megan Jacobson , Steve Kuhn , Alexander Peters , Tim Nagi , Sam Stewart , Zack Torstrick , Mathieu Ndong , Rob Anthony , Hengzhi Chen , Alex Howe , Nicholas Badger , Matthew Miller , Brad Vest , Ben Foster , Logan Rice , Alegra Aulie , Amanda Grovom , Philip Kasavan , Lewis Elliott

The Large-area multi-Institutional Scintillator Array (LISA) will detect high-energy neutrons in experiments with fast rare isotopes. The LISA allows for the study of unbound nuclei as well and many unknown higher-lying unbound states in light neutron-rich nuclei (Z$<$9). Nine primarily undergraduate institutions designed, proposed, and constructed this highly efficient large-area neutron detector that uses an array of 144 individual plastic scintillators to produce a position sensitive system with multi-hit capability. The construction process and characteristics of the detector will be presented.    [Preview Abstract]

 



EA.00094: Time resolution tests of Fine Mesh Photo Multipliers for the CLAS12 Central Time-of-Flight Detector
A. Reustle , V. Baturin

The upcoming CLAS12 Central Time-of-Flight (CTOF) system at Jefferson Lab's Hall B detector will feature a new barrel scintillation detector for identifying particles in that region by TOF-momentum relations. The region will experience a high magnetic field (5T) so the Photo-Multiplier Tubes (PMTs) measuring the scintillations will need to be shielded from this field. New Fine Mesh (FM) PMTs are unaffected by these high Magnetic Fields and would not require the otherwise necessary magnetic shielding of older Linear Focused (LF) PMTs. The question arises whether these FM PMTs produce results refined enough to distinguish between scintillations caused by different species of particles. To distinguish between the Pions, Kaons {\&} Protons expected in the CTOF's given region The PMT's must have a Timing resolution of $\sim $50 ps. To test the Timing resolution of FM PMTs we produced an apparatus consisting of a scintillator and acrylic light guides with one of each type of PMT attached at either end. Directed low level, low frequency light was provided via angled LEDs in perfect optical contact with the scintillator, to reproduce the scintillations caused by ionizing particles as closely as possible. The timing resolution of the Fine Mesh PMT was measured at double that of the Linear Focused PMT, within the margin of acceptability for our detector.    [Preview Abstract]

 



EA.00095: Transverse Flow of light clusters in Nuclear Reactions
J.A. Rodriguez-Lopez , C.M. Ko , J. Xu

Heavy-ion reactions induced by neutron-rich nuclei allow us to study the properties of isospin-asymmetric nuclear matter, specially the density dependence of nuclear symmetry energy. In previous works, light clusters production and their collective flow have been proven to be sensitive to the density dependence of nuclear symmetry energy. By means of a coalescence model based on an isospin-dependent Boltzmann-Uehling-Ulenbeck transport model with a momentum-dependent interaction, we have studied the yield, energy distribution, and transverse flow of light charged particles. We have further used different nuclear symmetry energies in the IBUU model to study their effects on the transverse flow of light charged particles.    [Preview Abstract]

 



EA.00096: Feasibility of 238U NRF Detection in Shipping Containers
Ben Ryan

Sophisticated detection methods are required to efficiently screen the immense volume of containers imported into the United States for the presence of special nuclear materials. The likelihood of detection of characteristic nuclear resonance fluorescence (NRF) lines for the 238U isotope inside a shipping container is examined. Similarly to atoms, nuclei fluoresce when they are excited by incident photons of particular energies unique to each isotope. Detection of the resulting gamma transitions induced by a $\gamma$-source allows for nonintrusive interrogation of materials. The Geant4 Monte Carlo simulation toolkit was modified to support detection of NRF. Simulations of a number of typical cargo container geometries containing natural uranium irradiated by a realistic nearly monoenergetic tunable gamma source were developed. The existence of NRF lines in the resulting spectra of exterior detectors will be described.    [Preview Abstract]

 



EA.00097: Monte Carlo Simulations for a Quadrupole Band Pass Filter for LANSCE Protons
Salah Salah , Jerry Peterson

As we know that protons have a positive charge, which means that if they hit any material, they will ionize it. This issue is a big problem for circuit researchers and indeed it is a problem for NASA and particle accelerator users. Thus, in this research, we have built a conceptual design consisting of two quadrupole magnets to select a ``band pass'' energy spectrum from the continuous proton spectrum at the LANSCE facility. We have found that we will be able to control and collect the desired protons with adequate rate and energy resolution. Thus, we will be able to create a new facility to measure the effect of 50 -- 700 MeV protons on electronic circuits.    [Preview Abstract]

 



EA.00098: Pion Reconstruction for Calibration of the PHENIX Muon Piston Calorimeter in Au+Au Collisions at RHIC
Scott Sanowitz

The PHENIX Muon Piston Calorimeter (MPC) is a useful tool for analyzing p+p, d+Au, Au+Au collisions at RHIC. Covering forward and backward pseudorapidities (3.1 $< \vert \eta \vert <$ 3.7) the detector has already been used in p+p and d+Au analyses. We are currently calibrating the detector for use in analyzing Au+Au data. Pion reconstruction is one of several methods by which to calibrate the towers of the MPC. Progress on these calibrations will be reported.    [Preview Abstract]

 



EA.00099: Mapping of the magnetic field for the NPDGamma Experiment
S. Jasmin Schaedler , Stefan Baessler , Septimiu Balascuta , Seppo Pentilla

In the NPDGamma-experiment the parity-violating weak meson exchange forces in the reaction $\overrightarrow{n} + p \rightarrow d+ \gamma$ are studied by measuring the angular correlation $A_{\gamma}$ of the emitted photons with respect to the direction of the neutron spin. The experiment is presently being setup at the Fundamental Physics Beam Line of the Spallation Neutron Source in Oak Ridge, TN. From the exit of the polarizer to the liquid Hydrogen target, the cold neutrons are moving in an almost vertical magnetic field. For the field calibration and adjustment a set of four guide coils and four shim coil systems are used. The strength and the direction of the field are measured using two magnetic flux gate sensors. The field magnitude is required to be 98~mT and the vertical field gradient less than 2.2~$\mu$T/cm between the spin flipper and the end of the target. The magnetic field in the target volume has to be vertical better than 2~mrad, to decrease the systematic errors. The measuring procedure and the mapping of the B-field will be presented.    [Preview Abstract]

 



EA.00100: Constructing a Radon Scrubber for Air
Andrew Schmitz , Xiaoyi Yang , Dongming Mei , Vincente Guiseppe , Chao Zhang , Yongchen Sun , Jason Spaans

A recurring problem in low background physics is the presence of the decay products of 222Rn (radon). The particularly treacherous aspect of radon is its gaseous nature and the long half-life of its daughters. Many industrial devices for air radon removal are sold on the market, but none achieve the removal factor required by our experiments in DUSEL. Therefore, we must design our own system to remove the radon from the air. This paper will show a radon removal system that we built at USD using charcoal. We constructed a single charcoal column system to perform a ``spike'' test, where a chamber is used to gather large amount of radon and then flushed with nitrogen. The radon arrives in the charcoal in the form of a pulse. This technique will allow us to better understand the adsorption and desorption properties of the charcoal under specific flow rates and pressures. A large pressure swing system will be built after the spike test.    [Preview Abstract]

 



EA.00101: Proton Induced X-ray Emission Spectroscopy of Red Wine Samples Using the Union College Pelletron Accelerator
Katie Schuff , Scott LaBrake

A 1-megavolt tandem electrostatic Pelletron particle accelerator housed at Union College was used to measure the elemental composition and concentration of homemade Cabernet and Merlot red wine samples. A beam of 1.8-MeV protons directed at an approximately 12-$\mu$m thin Mylar substrate onto which 8-$\mu$L of concentrated red wine was dried caused inner shell electrons to be ejected from the target nuclei and these vacancies are filled through electronic transitions of higher orbital electrons accompanied by the production of an x-ray photon characteristic of the elemental composition of the target. This is the PIXE Method. Data on the intensity versus energy of the x-rays were collected using an Amptek silicon drift detector and were analyzed to determine the elemental composition and the samples were found to contain P, S, K, Cl, Ca, Sc, Mn, Al, Fe, {\&} Co. Elemental concentrations were determined using the analysis package GUPIX. It is hypothesized that the cobalt seen is a direct result of the uptake by the grapes and as a product of the fermentation process a complex of vitamin B12 is produced.    [Preview Abstract]

 



EA.00102: Measuring the Timing Resolution of a Fine-Mesh PMT Under High Magnetic Fields
Arun Selvaratnam , Vitaly Baturin

The upgraded particle accelerator in Jefferson Lab requires that the detectors in Hall B also be upgraded, so they may cope with its increased power. The CLAS12 Central Time-of-Flight detector will use a new barrel scintillation detector that will be exposed to high magnetic fields ranging up to 5 Tesla. Traditionally, linear focused photomultiplier tubes have been used to determine time-of-flight valuations for charged particles resulting from particle accelerator experiments. However, without heavy shielding, a linear focused PMT will not be able to function in a high magnetic field. A new breed of ``fine-mesh'' PMTs claim to be unaffected by magnetic fields ranging up to 0.8 to 1.2 T. Our setup consists of a fine-mesh PMT that will receive diffused LED light while different magnetic fields are pointed towards it. The light will travel through wavelength-shifting fiber optic cables to a reference linear focused PMT located outside the magnetic field. Prior studies have only been done with a point-like light source on the PMT within the field. We will find what effects high magnetic fields have on fine-mesh PMTs.    [Preview Abstract]

 



EA.00103: Event Reconstruction in a Time Projection Chamber Designed to Make High Precision Fission Cross Section Measurements
Sarvagya Sharma

The Time Projection Chamber (TPC), being constructed by the NIFFTE (Neutron Induced Fission Fragment Tracking Experiment) collaboration will be used for high-precision fission cross-section measurements. These measurements will aid in the design of future generations of nuclear power plants. The track reconstruction effort in the NIFFTE experiment consists of a variety of statistical estimators to perform track finding and fitting. The Hough Transform is a brute force attempt at finding tracks that isolates features in the TPC volume through data binning. To determine track fit parameters, an iterative Kalman Filter has been implemented that accounts for multiple scattering. Comparing simulated and reconstructed tracks have shown the validity of these track reconstruction methods. In my poster, I will describe these methods in detail and I will also display the results we have achieved using these routines, including the first reconstructed tracks from our prototype TPC.    [Preview Abstract]

 



EA.00104: Improving the angular resolution for the silicon detectors of the STARS array
John Shaw , Benjamin Pauerstein , Danyi Chen , Timothy Ross , Richard Hughes , Con Beausang

The STARS (Silicon Telescope Array for Reaction Studies) array at LBNL is used to measure the emission angles of light charged particles (protons, deuterons and tritons) following transfer reactions. The array consists of two CD-shaped silicon energy detectors: a thin ``delta E'' detector and a thicker ``E'' detector, each segmented into twenty-four concentric rings. The angle at which a particle hits the delta E detector is typically approximated in the off-line analysis code as the angle from the beam axis to the center of the ring traversed by the particle. To improve angular resolution, a new method of approximating the angle was investigated. It was thought that energy loss in the delta E could be used to derive angle. SRIM was used to create functions of energy loss per unit distance with respect to particle energy. These functions were used in Fortran codes to create matrices of energy loss for a range of angles and final energies. The matrices were then worked into the off-line analysis code. Preliminary results will be shown. This work is partly supported by the DOE under grant numbers DE-FG02-52NA26206 and DE-FG02-05ER41379.    [Preview Abstract]

 



EA.00105: Exploring the Relationship between Intensity and Readout Delay in the WNSL Data Acquisition System
Nikolay Shenkov , Tanveer Ahmed , Mirela Fetea , Tan Ahn , Andreas Heinz , Desiree Radeck , Volker Werner

While the readout delay as a parameter of the Data Acquisition System (DAQ) is important in the detection of nuclear events and their lifetimes, every aspect of timing in a DAQ needs to be understood in order to get good data. Time correlations of the order of microseconds or more, larger than ones of nano-seconds we mostly used so far, are needed to identify isomers which was motivation for us to experimentally determine timing properties of the Wright Nuclear Structure Laboratory (WNSL) DAQ. Using 137Ba as a standard source of well known intensities, the effect of different delays on intensities of detected peaks was explored for the Data Acquisition System at the WNSL. The resultant data from the Time to Digital Converters (TDC) and Analog to Digital Converters (ADC) was sorted, plotted and analyzed. The results of our test measurement will be presented.    [Preview Abstract]

 



EA.00106: Polarized ($\gamma $,n) reaction studies of $^{nat}$Cd, $^{nat}$Sn, and $^{181}$Ta
Clarke Smith , Gerald Feldman

Asymmetrical ($\gamma $,n) and ($\gamma $,f) neutron yields from polarized photons incident on fissile and non-fissile nuclei make it possible to construct isotopic signature curves useful for cargo interrogation. The High Intensity Gamma-Ray Source (HIGS) provides tunable, nearly mono-energetic $\gamma $ rays with high intensities and circular or linear polarization by colliding electrons with laser photons at the Duke Free Electron Laser Laboratory. HIGS was used to measure asymmetries in neutron emission from linearly polarized $\gamma $ rays incident on $^{nat}$Cd, $^{nat}$Sn, and $^{181}$Ta targets. An array of 18 liquid-scintillator detectors at six angles in the range $\theta $ = 55$^{\circ}$-142$^{\circ}$ was used to detect neutrons both parallel and perpendicular to the plane of polarization at six photon energies between 11.0 and 15.5 MeV. Since $^{nat}$Cd, $^{nat}$Sn, and $^{181}$Ta are non-fissile, any measured asymmetries resulted unambiguously from the ($\gamma $,n) reaction because the ($\gamma $,2n) threshold was above the incident photon energies. Neutrons were distinguished from Compton-scattered photons by pulse-shape discrimination and timing information, and their energies (E$_{n})$ were determined via time-of-flight techniques using a 0.5 meter flight path. The characteristic plots of the parallel/perpendicular ratio of neutron counts as a function of neutron energy E$_{n}$ were constructed and compared to those of previously studied targets at HIGS, including fissile nuclei such as $^{235}$U, $^{239}$Pu, and $^{232}$Th.    [Preview Abstract]

 



EA.00107: Assessing the Effects of Magnetic Fields on the Photomultiplier Tubes in the SANE
Forrest Smith

As nuclear physicists work to understand the behavior of the quarks and gluons that comprise nucleons, polarization has become increasingly important. The Spin Asymmetries of the Nucleon Experiment (SANE) at Jefferson Lab used polarization of both beam and target in electron-proton scattering. While the beam can be produced in a polarized state, the target was polarized by way of a strong magnet. This magnet's field was non-negligible outside of the intended region, and this study examined the field and assessed its effect on photomultiplier tubes (PMTs) used in SANE. The magnetic field was mapped with reference to the location of the PMTs, and a statistical analysis of run data from SANE was done using the physics analysis framework developed ROOT. It was concluded that the magnetic field caused, on average, a 3.3{\%} \underline {+} 1.8{\%} loss in PMT signal due to the bending of electrons. This minor, but statistically significant, effect is consistent with prior, cursory estimates and solidifies the viability of coming results from SANE. These results also provide a good characterization for the PMTs' performance in a magnetic field and will benefit future experiments in which they are used.    [Preview Abstract]

 



EA.00108: Modeling of Polarized Electron-Proton Elastic Scattering in Collider Kinematics
Caroline Sofiatti

The Electron-Ion Collider (EIC) is a proposed new facility designed to collide high-energy polarized electrons with nuclei and polarized protons. The EIC is an essential step towards the next frontier in understanding the fundamental quark-gluon structure of matter. The electron- proton (e-p) program aims at precisely imaging the sea quarks and gluons in the nucleon. The goal of this project is to model the elastic e-p cross section and polarization asymmetry, at the conditions of relevance for the EIC. The concept of cross section is used to express the likelihood of interaction between particles; therefore, it provides important information about the nature of quarks and gluons. The development of the formalism for this reaction makes it necessary to reframe the electron scattering kinematics into the conditions of the EIC. Ultimately, documentation and computer codes regarding the modeling will be made available for future use by the EIC community.    [Preview Abstract]

 



EA.00109: Characterization and Resolution of VANDLE Modules
Irena Spassova , D.W. Bardayan , J.C. Blackmon , J.A. Cizewski , R.K. Grzywacz , M. Madurga , B. Manning , C. Matei , E. Merino , P.D. O'Malley , S. Paulauskas , W.A. Peters , F. Raiola , F. Sarazin , D. Walter

The Versatile Array of Neutron Detectors at Low Energies (VANDLE) is being developed to study the properties of unstable nuclei via (d,n) reactions and beta-delayed neutron emission. It is composed of scintillator bars of two sizes, 60 cm and 2 m, coupled to photomultiplier tubes. Twenty of these bars have been constructed into VANDLE modules and voltages have been gain matched for various energy ranges, and attenuation lengths measured. Measurements were recorded for position and timing resolutions of each module. The results of these characterizations with respect to different assembly parameters will be presented.    [Preview Abstract]

 



EA.00110: MCPR -- A Monte Carlo model for studies of Fragmentation Reactions
Hannah Staley , Jorge Pereira

Fragmentation reactions are nowadays one of the most successful mechanisms to produce new unknown nuclear species. Nuclear reactions have the standard direct and compound-nucleus reactions components. Also there exists abundant evidence of an intermediate process that seems to fall in between these two types, and is more than just a combination of them. This in between state, the so-called pre-equilibrium stage, is less clearly understood. So, there are many models to describe pre- equilibrium reactions. In the present work, a systematic study of fragmentation-reaction data has been carried out, using the new Monte Carlo Pre-equilibrium code MCPR. The model combines a pre-equilibrium stage with the ABLA evaporation model, based on the statistical de-excitation model. Particle spectra; angular distributions; fragment distributions; excitation functions, along with production cross sections, were calculated for a large group of reactions. We particularly are interested in energies and elements studied at the National Superconducting Cyclotron Laboratory, NSCL. Here energies of 80 to 150 MeV/u and masses $\sim$ A=20-200 are typically used.    [Preview Abstract]

 



EA.00111: Nuclear Reaction Calculations relevant for p-process nucleosynthesis
Benjamin Stefanek , Artemis Spyrou

The p-process is an important nucleosynthesis process and essential in the creation of heavy, proton-rich atomic nuclei. The environment where we are investigating the p-process is in core-collapse supernovae. Under such conditions the flux of energetic photons is high, and the p-process can occur through photo-induced reactions on pre-existing s-nuclei. Because of the difficulty of reproducing gamma-alpha and gamma-proton reactions in the lab, we analyze the reactions in reverse. Astrophysical calculations on the abundance of p-nuclei use nuclear input from the Hauser-Feshbach model, which depends on several nuclear parameters. The alpha particle optical model potential and a parameter describing nuclear level densities above the region of discrete levels are two such parameters. In light of these facts, we calculate production cross sections for P-nuclei under various existing parameterizations using the nuclear reaction code Empire. By doing this we hope to understand how production cross sections vary as isotopes further away from stability are considered. The overall goal is to compare the differing predictions to data that will be gathered from future experiments at the NSCL.    [Preview Abstract]

 



EA.00112: M1 width of the 2$_{1}^{+}$ state in $^{22}$Na and searches for tensor contributions to beta decays
Steven Steininger , Alejandro Garcia , Smarajite Triambak , Devin Short , David Williams

A determination of the $\beta \quad - \quad \gamma $ angular correlation from $^{22}$Na beta decay with the GAMMASPHERE array has been used to extract induced-tensor-currents contributions to the weak interaction. The result, together with other available experimental data yielded an unexpectedly large induced tensor (second class) component to the hadronic current, which is at variance with the Standard Model. A weak link in the data used for this analysis is another recoil-order term, the weak magnetism form factor, which was extracted from an independent unpublished determination of the analog isovector magnetic dipole (2$^{+}$ $\to $ 3$^{+})$ gamma-ray transition strength in $^{22}$Na with low statistics and significant backgrounds. We are currently running an experiment to measure the $\Gamma _{M1}$ value from E$_{x}$ = 1952 keV state using a well known 21Ne(p, $\gamma )$ resonance at Ep = 1112 keV. This resonance leads to a gamma cascade in 22Na at E$_{x}$ = 7800 $\to $ 1952 $\to $ 0 keV. We will use a $\gamma -\gamma $ coincidence setup with a 120{\%} HPGe detector and a large 10 $\times$ 10 NaI detector. This method will provide both high detection efficiency and reduced backgrounds.    [Preview Abstract]

 



EA.00113: Production of Short-Lived $^{37}$K
Heather Stephens , Dan Melconian , Praveen Shidling

The purpose of our work during the summer months of 2010 was to produce a beam of $^{37}$K with $\ge $ 99{\%} purity and characterize in detail the remaining contaminants. A projectile beam of $^{38}$Ar at 25 and 29 MeV/nucleon from the K500 cyclotron generated the $^{37}$K by reacting with an H$_{2}$ gas target. The \textit{MARS} spectrometer was then used to separate the reaction products of interest from the primary beam and other unwanted reaction products. From analysis of our production experiment, we were able to successfully produce 807 counts/nC of $^{37}$K with 99.19{\%} purity at 25MeV/u and 1756 counts/nC with 98.93{\%} purity at 29MeV/u. The purity of this beam and rate of production is more than adequate for use in determining the half-life of $^{37}$K, the next step to be done by the team in August 2010. This measurement will be accomplished by implanting the activity into a Mylar tape, placing it between two high-efficiency gas counters and counting the amount of beta decays as a function of time. It is expected the half-life will be measured using the $^{37}$K produced from $^{38}$Ar at 29MeV/u.    [Preview Abstract]

 



EA.00114: Construction of Liquid Hydrogen and Deuterium Targets for E906/SeaQuest
Michael Stewart

E906/SeaQuest at Fermi National Accelerator Laboratory is a fixed target experiment which will examine the sea quark structure of the proton. Specifically, SeaQuest will look at the production of pairs of muons and anti-muons resulting from Drell-Yann interactions in liquid hydrogen and deuterium targets in order to measure the $\bar{d}$ to $\bar{u}$ asymmetry in the proton. In order to perform this experiment, cryogenic targets are used that are 50 cm long and 7.5 cm in diameter. These liquid hydrogen and deuterium targets will be operated at 20 K, with beam heating of 30 J per minute. Cryocoolers have been acquired and condensers designed and fabricated. These have been tested with heat loads similar to those which will be produced by the beam. The design of the SeaQuest cryogenic target system and the performance data collected during the target tests performed in the laboratory will be presented.    [Preview Abstract]

 



EA.00115: Modifying the Crystal Ball and Developing Data Acquisition Software
Alexey Strakovsky , Baya Oussena

This poster describes work done with the A2 Collaboration at the Johannes Gutenberg Universitaet (JGU) in Mainz, Germany. In 2009, we modified the cabling of the Crystal Ball detector, housed at the Mainzer Mikrotron facility (MAMI) at JGU. This reduced the length of the 672 signal cables by approximately 43.68 km to reduce weight on the frame of the detector and make room for a frozen-spin hydrogen target. This involved cutting cables in half and resoldering the ends to new interface cards and photomultiplier tube connectors. More recently in 2010, our focus has been to develop new data acquisition software to replace the one currently in use. The new version, AcquDAQ, is based on C++ rather than the old C programming language. When completed, AcquDAQ will control and read data from the new electronics hardware utilized at MAMI, including the Crystal Ball.    [Preview Abstract]

 



EA.00116: Development of a High-Rate Ionization Counter
Sabrina Strauss , D.W. Bardayan , K.Y. Chae , J.A. Cizewski , W.A. Peters , K.T. Schmitt , M.S. Smith

Ionization counters are useful for the determination of beam composition and beam normalization in many nuclear physics experiments. At the Holifield Radioactive Ion Beam Facility (HRIBF), we have developed and are currently testing a new ionization counter that will count and accurately identify particles at rates up to 10$^{6}$ pps. The new ion counter is based on the tilted electrode gas ion chamber (TEGIC) model developed at RIKEN [1] and consists of alternating anodes and cathodes, effectively creating a stack of ion chambers. Design and results from preliminary testing will be presented. \\[4pt] [1] Kimura \textit{et al.}, Nucl. Instr. And Methods A \textbf{538} 608 (2005).    [Preview Abstract]

 



EA.00117: Quality Assurance Testing of RPC Modules for the PHENIX Muon Trigger Upgrade
Kyle Sullivan

The Relativistic Heavy Ion Collider (RHIC) collides polarized protons to answer fundamental questions regarding the angular momentum of the proton. The PHENIX collaboration is preparing to measure single spin asymmetries of muons from the decay of W bosons in polarized p+p collisions produced by the RHIC collider. An upgrade to the PHENIX muon trigger is necessary to accomplish this goal. Much of this upgrade has already been completed. New front end electronics (FEE) have already been installed on the existing muon tracking system and a station of resistive plate chambers have been installed in the North Arm. This summer, Muhlenberg College contributed to the assembly of a South RPC station. This poster will describe the quality assurance testing of the individual RPC modules as well as the attachment of the FEE boards to the modules. The modules are tested for noise, dark current, gas leaks, efficiency, and cluster size. In addition, the effect of changing the high voltage and thresholds is studied.    [Preview Abstract]

 



EA.00118: Analyzing Photoproduction Data at the CB-ELSA Experiment to Establish Missing Hadronic Resonance States
Matthew Szmaida

The structure and dynamics of the nucleon and its excited states has been the subject of much inquiry since the discovery of the $\Delta $ resonance in the early 1950s. Typically, research into nucleon structure entails acquiring large data sets with input from several experiments using different mechanisms. New resonance states cannot be found by looking at simple spectra. Without precise data from many different nucleon decay channels, it remains difficult or even impossible to accurately determine the properties of well established resonances, or to confirm or rule out the existence of weakly established resonances or new, so-far not observed states. The current challenge is to search for new states and to measure the properties of some of the known higher-lying nucleon states with masses between 1.7 and 2.5 GeV/c$^{2}$. By studying the isospin-selective reaction $\gamma $p$\to \Delta \omega \to $p$\pi ^{0}\omega $, it is possible to isolate contributions from individual excited states and to clarify their importance. In this reaction, only $\Delta $* resonances can contribute in the intermediate state; N* states are excluded due to the zero isospin of the $\omega $ meson. The data for the project were taken with the Crystal-Barrel/TAPS experiment at the Electron Stretcher Accelerator at the University of Bonn, Germany.    [Preview Abstract]

 



EA.00119: Development of TReRaC Program for Stellar Explosion Research
Kyle Thomsen , Michael Smith

Hundreds of different thermonuclear reactions drive a star through its life cycle. If a star's death results in an explosion, elements created by these fusion reactions can be spread throughout the cosmos and ultimately form new stars, planets, and sometimes life. In an effort to further understand what happens when these reactions take place, researchers carry out both lab measurements and simulations to test the most current ideas about the origins of the elements. To better estimate the rates of these reactions, the Thermonuclear Reaction Rate Calculator (TReRaC) program has been written. The strength of this program lies in its acceptance of a wide variety of nuclear physics information as input and its incorporation into the Computational Infrastructure for Nuclear Astrophysics (CINA) -- a suite of tools available to researchers around the world for nuclear astrophysics research. Among the information that TReRaC is capable of handling are each resonance's energy, spin / parity, entrance and exit channel widths, as well as non-resonant capture parameters. Currently, the code is capable of matching test rates to within the accuracy of the input, and we are finalizing the treatment of broad resonances.    [Preview Abstract]

 



EA.00120: Slow Control System for the NIFFTE High Precision TPC
Remington Thornton

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) has designed a Time Projection Chamber (TPC) to measure neutron induced fission cross-section measurements of the major actinides to sub-1\% precision over a wide incident neutron energy range. These measurements are necessary to design the next generation of nuclear power plants. In order to achieve our high precision goals, an accurate and efficient slow control system must be implemented. Custom software has been created to control the hardware through Maximum Integration Data Acquisition System (MIDAS). This includes reading room and device temperature, setting the high voltage power supplies, and reading voltages. From hardware to software, an efficient design has been implemented and tested. This poster will present the setup and data from this slow control system.    [Preview Abstract]

 



EA.00121: Optimization and Accessibility of the Qweak Database
Erik Urban , Damon Spayde

The Qweak experiment is a multi-institutional collaborative effort at Thomas Jefferson National Accelerator Facility designed to accurately determine the weak nuclear charge of a proton through measurements of the parity violating asymmetries of electron-proton elastic scattering that result from pulses of electrons with opposite helicities. Through the study of these scattering asymmetries, the Qweak experiment hopes to constrain extensions of the Standard Model or find indications of new physics. Since precision is critical to the success of the Qweak experiment, the collaboration will be taking data for thousands of hours. The Qweak database is responsible for storing the non-binary, processed data of this experiment in a meaningful and organized manner for use at a later date. The goal of this undertaking to not only create a database which can input and output data quickly, but create one which can easily be accessed by those who have minimal knowledge of the database language. Through tests on the system, the speed of retrieval and insert times has been optimized and, in addition, the implementation of summary tables and additional programs should make the majority of commonly sought results readily available to database novices.    [Preview Abstract]

 



EA.00122: Monte Carlo Simulation of the DRAGON Recoil Mass Spectrometer End Detectors
Laurelle Veloce , J. Fallis , C. Ruiz , S. Reeve

DRAGON (Detector of Recoils And Gammas Of Nuclear reactions), located at TRIUMF in Vancouver, BC, is designed to study radiative capture reactions relevant in astrophysical nucleosynthesis processes. These types of reactions help us understand the production of heavy elements in the Universe. An accelerated beam of a given isotope is sent through a gas target where the reactions take place. Magnetic and electrostatic dipoles separate the recoils from the original beam particles, selecting particles according to charge and mass. The products of the nuclear reactions are then detected at the end of DRAGON by heavy ion detectors, which constitute two micro channel plate (MCP) detectors for time of flight measurements, used in conjunction with a Double Sided Silicon Strip Detector (DSSSD) or an ionization chamber (IC). The DSSSD gives information on number of counts, total energy deposited, and position while the IC measures the number of counts and the energy deposited as the particle travels through the chamber. In order to determine which set up is ideal for a given reaction and energy range, we have developed a Monte Carlo simulation of these end detectors. The program simulates both recoil and beam particles, and takes into account effects such as straggling and pulse height defect. Reaction kinematics in the gas target are also considered. Comparisons to recent experimental data will be discussed.    [Preview Abstract]

 



EA.00123: Simulation of Photodisintegration Process with Polarized $\gamma$-ray Beams
James Walker

Large asymmetries were observed in the angular distributions of photo-neutrons produced in the interaction of polarized gamma rays with a variety of targets. In the experiments at high intensity gamma ray source at the Triangle Universities Nuclear Laboratory a survey of physically interesting and/or otherwise important nuclei has been initiated using $\gamma$-ray energy 6-15 MeV In this experiment backgrounds could come from ($\gamma$,n) on nitrogen in the target room, from scattering on the detector mount, or from neutrons scattering from one detector to another. GEANT4 simulations were necessary in order to evaluate the importance of different background sources. GEANT4 applications suitable for simulating the experimental set-up were developed and used to evaluate relevant backgrounds.    [Preview Abstract]

 



EA.00124: A New Calibration Technique for the ALICE Electromagnetic Calorimeter at the Large Hadron Collider
E. Watkins , M. Perales , M. Cervantes , E. Garcia-Solis , S. Sakai , M. Ploskon , P. Jacobs

The Large Hadron Collider at CERN is the world's largest and highest energy, particle and heavy ion collider. The LHC will explore the frontiers of particle physics using high energy proton+proton collisions and the properties of the Quark-Gluon Plasma through the collision of heavy nuclei at high energy. ALICE is one of the four LHC experiments, specialized for the study of heavy ion collisions. This study presents a new technique for the calibration of an essential detector of ALICE - the EMCal. We utilize various computational techniques and analyze proton-proton collision data recorded at 900 GeV. The ALICE TPC is used to isolate the tracks of e+e- pairs that originate from the decay of j/psi particle and that fall within the EMCal's acceptance. The TPC measures the momentum of these electron tracks, which is compared to the energy deposited by them in the EMCal. We therefore use the precise measurement of TPC momentum as the reference to calibrate the EMCal energy measurement. In this presentation we will show the steps taken to analyze the data from the TPC, how we performed the matching of electron tracks from the j/psi decay with the energy deposited in the EMCal, and some preliminary results of this calibration technique. Research funded by NSF and DoE.    [Preview Abstract]

 



EA.00125: High-Purity Germanium Characterization
Nick Weinandt , Yongchen Sun , Dongming Mei

Underground germanium crystal growth is a main focus of the CUBED 2010 research in the state of South Dakota where the DUSEL will be hosted. High-purity germanium is essential to the construction of germanium detectors for neutrioless double-beta decay and dark matter experiments planned for DUSEL. The characterization of germanium ingots and crystals is an important part of the high-purity germanium crystal growth process. Through the characterization process, we can learn important information such as net impurity concentration and crystal structure. The information can be fed back to the zone refining and crystal growth processes. Resistivity measurements and Hall Effect experiments were used to understand the impurity concentration of the germanium bars. Both experiments were run at 77K to avoid thermal conductivity. When resistivity and Hall Effect experiments are coupled with future research into and Spectroscopies, we can begin to understand exactly what impurities are present in the sample. With resistivity, the Hall Effect, Photo-Thermal Ionization Spectroscopy, and Deep-Level Transit Spectroscopy, we can gain a more complete understanding of the characterization techniques and the growing of the crystal. At the conference I would be able to show the results obtained from our experiments    [Preview Abstract]

 



EA.00126: Tagging the Decay of Neutron Unbound States near the Dripline
Alissa Wersal , Greg Christian , Michael Thoennessen , Artemis Spyrou

Near the neutron dripline the study of neutron-unbound states is a valuable spectroscopic tool. Neutron-decay spectroscopy experiments, however, only determine the relative energy of the resonances. If the neutron decays to a bound excited state, it is necessary to measure the $\gamma$-decay in order to determine the absolute excitation energy of the initial state. The CAESium iodide ARray (CAESAR) was used for the first time in coincidence with the MoNA/Sweeper setup at the NSCL to perform this type of experiment. A secondary 70 MeV/u $^{32}$Mg beam produced at the Coupled Cyclotron Facility bombarded a 288 mg/cm$^{2}$ beryllium target. After the reaction, any charged particles were deflected by a superconducting 4T large-gap dipole magnet, and their positions, time of flight, and energy loss were measured. Neutrons were detected in coincidence with the Modular Neutron Array (MoNA) while CAESAR recorded any possible gamma rays. The Doppler shifted calibration of CAESAR was performed with gamma rays from Coulomb excited $^{32}$Mg and from $^{30}$Na fragments. Preliminary results will be presented.    [Preview Abstract]

 



EA.00127: Implanted $^3$He Targets for Inverse Reaction Studies with Radioactive Ion Beams
J.L. Wheeler , R.L. Kozub , S.A. Graves , D.J. Sissom , D.W. Stracener , D.W. Bardayan , C. Jost , P.D. O'Malley

Proton transfer reactions, such as ($^3$He,d), are extremely important for measuring the properties of single particle states and resonances. Many such resonances are important in the rp process of explosive nucleosynthesis, but cannot be measured via resonance scattering directly. For the ($^3$He,d) reaction, it is necessary to use localized $^3$He targets, and gas jet targets are expensive and difficult to construct. An alternative approach is to implant $^3$He into thin aluminum foils. We are continuing our project\footnote{D.J. Sissom \emph{et al.} http://meetings.aps.org/link/BAPS.2008.DNP.DA.92}$^,$\footnote{J.L. Wheeler \emph{et al.} http://meetings.aps.org/link/BAPS.2009.HAW.GB.133} of implanting $^3$He into 0.65 ${\mu}$m thick aluminum foils at the Holifield Radioactive Ion Beam Facility at ORNL. Target profiles are analyzed using Rutherford backscattering to determine the concentration and distribution of the implanted $^3$He. An update of these results and a detailed description of the procedures will be presented. This research is supported by the U.S. Department of Energy.    [Preview Abstract]

 



EA.00128: Production and Separation of Exotic Beams via Fragmentation Reactions Using MARS
Kenneth Whitmore , R.E. Tribble , B.T. Roeder , L. Trache

Radioactive nuclei away from the valley of stability are important in the study of nuclear astrophysical reactions. Because such nuclei cannot be found in nature, they must be produced in the lab in order to be studied. The Momentum Achromat Recoil Spectrometer (MARS) at Texas A\&M University is able to produce beams of radioactive nuclei and separate them from other products based on their charge, mass, and energy. Fragmentation reactions can produce a wider range of exotic beams at higher energies than other reaction mechanisms at lower energies. Reaction products from three different fragmentation reactions are studied, and production rates for various nuclei are determined and compared to predictions made by the simulation program LISE++. Production rate is related to the cross section, the kinematics and other particulars of a given reaction, and it is important to know how well the simulation can predict these rates. Work presented includes data from reactions with $^{36}$Ar at 45 MeV/u, $^{40}$Ar at 40 MeV/u, and $^{24}$Mg at 48 MeV/u, all on a $^{9}$Be target. These are the first fragmentation reactions to be studied with MARS.    [Preview Abstract]

 



EA.00129: Evaluation of the KATRIN Detector
Kevin Wierman

The KArlsruhe TRItium Neutrino experiment, (KATRIN), is designed to make a direct, model independent measurement of the electron neutrino mass with a sensitivity of .2 eV. A neutrino mass measurement will guide theory beyond the current Standard Model, which considers neutrinos to be massless, as well as modern cosmological models. KATRIN determines the neutrino mass by using magnetic adiabatic collimation and an electrostatic retarding spectrometer coupled to a 148 pixel PIN diode array to analyze the spectrum of electrons emitted during tritium beta decay. In addition to basic counting, the energy, spatial and temporal resolutions of the detector will be used to reduce systematic error. The detector performance was characterized using an $^{241}Am$ gamma source and a mono-energetic photoelectron source. The response to the electron source was used to monitor the thickness of the non-reactive dead-layer of the detector. The absolute detector efficiency is monitored to the 1\% level by comparing a femto amp photocurrent source to the electron rate in the detector. By March 2011, the system will be available for use in commissioning the rest of the KATRIN hardware in Karlsruhe, Germany.    [Preview Abstract]

 



EA.00130: Development of an Organic Liquid Scintillation Detector to be Used for Measuring Muon-Induced Processes at Homestake
Brian Woltman , Patrick Davis , Dongming Mei , Chao Zhang

Understanding the backgrounds produced by muon-induced processes is important to the success of experiments searching for rare event physics such as neutrinoless double-beta decay, dark matter, or neutrino oscillations, which require extremely low backgrounds. Measuring these muon-induced processes is vital for the low background experiments planned for Sanford Lab/DUSEL at the Homestake Mine in Lead, SD. We have constructed and calibrated a 12 liter liquid scintillation detector joined with two photomultiplier tubes (PMTs). We will present the construction and calibration of the detector, including its efficiency and neutron/gamma discrimination. We will also discuss the capabilities of our detector for use in low-background underground laboratories.    [Preview Abstract]

 



EA.00131: Extraction of Beam Spin Asymmetry in the $\vec {\gamma }d\to pp\pi ^-$ Reaction
Weizhi Xiong , Yordanka Ilieva

Here we present a new method to estimate the polarization observable beam spin asymmetry (Sigma) from experimental data on nuclear reactions initiated by linearly polarized photon beam. We use the Maximum Log-Likelihood (LL) method to determine the estimator for Sigma and its uncertainty. We construct the probability density function (p.d.f.) of the azimuthal angle ($\phi )$ according to the physics dependence of the cross section of a nuclear reaction on $\phi $, in which Sigma is a parameter. In order to test our estimator, we applied it to randomly generated events similar to real data from the $\vec {\gamma }d\to pp\pi ^-$ reaction occurring when a photon strikes a deuterium target. We analyzed samples generated with, and without, detector acceptance folded in the p.d.f., where we extract the functional dependence of the detector acceptance from data taken with the CLAS detector at Jefferson Lab. We find that the value of Sigma estimated from the LL method is consistent with the true value and our estimator is unbiased. We show that the LL method yields an estimate for Sigma that has a smaller uncertainty than estimates obtained from fits to azimuthal distributions. Ours is a new and original study which supports the rich N* physics program based on polarization observables that is currently being run in Hall B at JLab.    [Preview Abstract]