Bulletin of the American Physical Society
APS April Meeting 2010
Volume 55, Number 1
Saturday–Tuesday, February 13–16, 2010; Washington, DC
Session W1: Poster Session IV: Post-Deadline Abstracts (10:30AM-1:30PM) |
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Room: Exhibit Hall A-B |
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W1.00001: On a New Analysis of the Foundations of Classical Mechanics. I. Dynamics Temur Z. Kalanov The approach to the critical analysis of classical mechanics, based on formal logic, is proposed. From the logic point of view, the problem is that to identify a material point $M$, i.e. to establish the identity relation between concepts ``physical object $M$`` and ``mathematical object $M$''. The idea of the correct solution of this problem is as follows. As it is known, the material point $M$ is characterized by following quantities: mass $m_M $; position in system of coordinates at the moment of time $t$; velocity $\vec {v}_M (t)\;$; acceleration ${d\vec {v}_M } \mathord{\left/ {\vphantom {{d\vec {v}_M } {dt}}} \right. \kern-\nulldelimiterspace} {dt}$. If mass and velocity are essential (dynamic) properties (signs) of a material point $M$, then momentum $\vec {p}_M (t)\;\equiv \;m_M {\kern 1pt}\vec {v}_M (t)$ represents the dynamic identifier of a material point $M$. In this case, expressions for kinetic energy $E_M^{(kin)} {\kern 1pt}(t)\;\equiv \;{p_M^2 } \mathord{\left/ {\vphantom {{p_M^2 } {m_M \;=}}} \right. \kern-\nulldelimiterspace} {m_M \;=}\;m_M {\kern 1pt}v_M^2 (t)$ and for force $\vec {f}_M \;\equiv \;{d\vec {p}_M } \mathord{\left/ {\vphantom {{d\vec {p}_M } {dt}}} \right. \kern-\nulldelimiterspace} {dt}$ are consequences of this identifier. It means that $\vec {f}_M \;\equiv \;{d\vec {p}_M } \mathord{\left/ {\vphantom {{d\vec {p}_M } {dt}}} \right. \kern-\nulldelimiterspace} {dt}$ is a definition of force, and mass $m_M $ should be determined by other identifier. Force is a vector manifestation of energy. Thus, the logic approach to the analysis of classical mechanics leads to correct definition of force. [Preview Abstract] |
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W1.00002: Test of the Standard Electroweak Model in superallowed 0$^{+ }\to $ 0$^{+}$ nuclear $\beta $ decays A. Bey, B. Blank, G. Canchel, C. Dossat, J. Giovinazzo, I. Matea, V. Elomaa, T. Eronen, U. Hager, J. Hakala, A. Jokinen, A. Kankainen, I. Moore, H. Pentilla, S. Rinta-Antila, A. Saastamoinen, T. Sonoda, J. Aysto, N. Adimi, G. de France, J.-C. Thomas, G. Voltolini, T. Chaventre Precise measurements of superallowed $\beta $ decays provide demanding test of the fundamental symmetries of the electroweak interaction. Collectively, the corrected comparative half-lives of these transitions allow a sensitive probe of the CVC hypothesis. Moreover, by providing the most accurate determination of V$_{ud}$, the up-down quark-mixing element, these data serve as a stringent test of the unitarity of the CKM matrix of the Standard Model. However, prior to new results, the sum of squares of the top-row CKM elements failed to meet unity by more than 2 $\sigma $. As a possible explanation for this default, uncertainties in the Coulomb corrections applied to the experimental data were pointed out. It became therefore essential to extend the study to heavy odd-odd (A $\ge $ 62) and medium mass (18 $\le $ A $\le $ 42) nuclei where these corrections are predicted to be much larger. In this context, the $\beta -\gamma $ decays of $^{62}$Ga and $^{38}$Ca have been investigated at the IGISOL and ISOLDE facilities. The results obtained will be presented. Prospects for the continuation of this work will be also discussed. [Preview Abstract] |
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W1.00003: Status of the MICE Muon Ionisation Cooling Experiment Ben Freemire Muon ionization cooling provides the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. The muon ionization cooling experiment (MICE)* is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. A first measurement of emittance is performed in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one and a particle identification system provide a measurement of the outgoing emittance. In February 2010 it is expected that the beam and most detectors will be commissioned and the time of the first measurement of input beam emittance closely approaching. The plan of steps of measurements of emittance and cooling, that will follow in the rest of 2010 and later, will be reported. [Preview Abstract] |
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W1.00004: Lepton Jets: A New Dark Matter Signal at the LHC Alexander Burgers Recently, lepton-jets are predicted by theoretic models as a new type of Dark Matter signature in colliding beam experiments. These models are well motivated by recent astrophysical observations by the PAMELA and Fermi experiments. The LHC as a discovery machine will allow direct production of the Dark Matter particle as well as dark-photons, which could be the force carriers for Dark Matter particles and may be responsible for anomalous positron signals observed by PAMELA and Fermi. The new signature of Dark Matter is highly collimated, low $P_T$ multi-lepton events. Detection of such a signature poses several experimental challenges. The presentation will report a feasibility study of lepton-jet events with the ATLAS detector using fully simulated Monte Carlo events. The analysis shows that the large ATLAS muon spectrometer would have the best sensitivity to detect muon-jets at the LHC. [Preview Abstract] |
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W1.00005: What does SN1987A say about extra dimensions? Satheeshkumar Veerahanumak There has been a tremendous progress in the last decade in our efforts to confront the String-inspired ideas with experiments or observations. There are two approaches to this problem. One is to use the LHC data and other is to use astronomical data. Among the latter, using SN1987A data for placing the constraints on the models of extra dimensions is very popular. In this poster, we consider all the possible energy loss mechanisms of SN1987A and study the constraints they place on the number and size of extra dimensions and the higher dimensional Planck scale in the ADD scenario. [Preview Abstract] |
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W1.00006: Efimov Physics in Li-6 Atoms Daekyoung Kang, Eric Braaten, Hans-W. Hammer, Lucas Platter A new narrow 3-atom loss resonance associated with an Efimov trimer crossing the 3-atom threshold has recently been discovered in a many-body system of ultracold Li-6 atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the 3-body recombination rate in this region to determine the complex 3-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the 3-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at (672 +/- 2) G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the 3-body recombination rate at (759 +/- 1) G where the 3-spin mixture may be sufficiently stable to allow experimental study of the many-body system. [Preview Abstract] |
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W1.00007: Higher Order Chromaticity Correction for ELIC Hisham Sayed, Alex Bogacz The proposed electron collider lattice design with extremely low betas at the interaction Point IP ($\beta $*$\sim $ 0.5cm) and the precedently large longitudinal acceptance of the collider ring ($\Delta $p/p = 0.005) [1], makes the chromatic corrections of paramount importance. Here the chromatic effects of the final focus quadruples are corrected with two families of sextuples in a dispersive region; one family per plane. Each family consists of two pairs of sextuples located symmetrically around the interaction point IP. A confined dispersion wave around the IP is generated by two bending magnets (one at each side of the IP with mirror reflected Polarities) which also develop the vertical staking design. The resulting spherical aberrations induced by the sextuples are mitigated by design; the matching section optics features an inverse identity transformation between sextuples in each pair. A dedicated optics is placed in the matching region to implement sextuple orthogonality in both planes, which in turns minimizes the required sextuple strength and eventually leads to larger dynamic aperture of the collider. The betatron phase advances from the IP to the sextuples are chosen to eliminate the second order chromatic aberration. [Preview Abstract] |
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W1.00008: A Theoretical Study of some Rheological Properties of the Aggregation of the Molecules Deoxy- Hemoglobin S Francis Mensah, Julius Grant, Arthur Thorpe Sickle cell disease is a serious public health problem that affects many people worldwide. In this paper, the Langevin equation is used for hemoglobin's aggregation in sickle cell anemia. Several parameters are explored such as the time-dependent deformation of the aggregates whose plot gives a sigmoid, the time-dependent expressions obtained for the coefficient of viscosity and the elastic modulus which characterize the aggregation of the sickle hemoglobin. Other properties such as the viscoelastic and the elasto-thixotropic properties of the sickle hemoglobin polymer are also described. An attempt is made to approach the polymerization process in terms of a dynamical system. [Preview Abstract] |
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W1.00009: Measuring the Fierz Interference Term in Beta-Decay using Ultracold Neutrons Kevin Hickerson It is theorized that contributions to the Fierz interference term from scalar interactions beyond the Standard Model could be detectable in the spectrum of neutron beta-decay, manifest as a nonzero value for the so-called $b$ parameter. Some supersymmetric models could have $b$ as large as $10^{-3}$, which is within reach for measurement, but below the current limits set by superallowed $0+ \to 0+$ nuclear $\beta$-decays. We present a new experiment that uses the Ultracold Neutron (UCN) source at LANSCE in which UCN, which can be trapped inside material bottles, are guided to a $4\pi$ scintillator beta calorimeter, shielded from background generated by the pulsed spallation target. [Preview Abstract] |
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W1.00010: Faddeev Approach to Confinement in Three Quark Problems Joseph Day, Joseph McEwen, Zoltan Papp The spin=1/2 elementary particles, the baryons, are mostly described as three-quark configurations. The quarks obey relativistic quantum mechanics. Their mutual interaction is modeled by infinitely rising potentials whose short-range nature is mediated by the exchange of Goldstone bosons. We solve the relativistic three-quark problem by using the Faddeev method. In the Faddeev method we break the wave function into components, and the components satisfies somewhat better integral equations. Nevertheless, the solution was not possible without approximating and violating the asymptotically rising potential. In this work we overcome this problem. We devised an approximation method, which allows the exact calculation of the Green's operator of an asymptotically rising potential with semirelativistic kinetic energy operator by using matrix continued fractions. [Preview Abstract] |
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W1.00011: ABSTRACT WITHDRAWN |
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W1.00012: Automated spectral classification of Kepler's Supernova Remnant Stephen Reynolds, Kazik Borkowski, Timothy Canty The study of Kepler's Supernova Remnant gives astrophysicists a unique look into the details of supernovae. As Kepler's Supernova Remnant appears to be an unordinary thermonuclear remnant, the identification of spectrally unique regions could reveal insights into the mechanisms behind the event. Using observational X-ray data from the Chandra X-ray Observatory, we devised an automated method of classification, to identify areas of the image with unique spectroscopic properties. Although this data has already been manually evaluated, results of the clustering attempts show that there are unique features that a manual method may have missed. The automated results agree with previous studies into the supernova, and suggest that the presence or absence of magnesium may play a significant role in uncovering the details of the supernova event. [Preview Abstract] |
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W1.00013: Holes in Hall Effect Lianxi Ma Hall Effect can be used to determine the signs of current carriers in metals and semiconductors. It is well known that when electrons are current carriers, the Hall coefficient is negative, i.e. R$_{H}$\textit{$<$0}; when holes are current carriers, the Hall coefficient is positive, i.e. R$_{H}$\textit{$>$0}. However, puzzling arises regarding that in both scenarios, the essential moving particles are electrons. Therefore, there should not have any different effect in theory. We discuss the details about two situations and point out that both quantum and classical mechanics give same current direction under external electric field. However, under the influence of external magnetic field, because the mass of electrons is negative at valence band, electrons move to the opposite direction of its Lorentz force, which behave like a positive charge and give positive R$_{H}.$ [Preview Abstract] |
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W1.00014: Pulsar Timing Arrays Can Measure Gravitational Wave Source Distance Xihao Deng, Lee Samuel Finn Gravitation waves manifest themselves as a tidal acceleration; correspondingly, gravitational wave detectors must be analyzed as (space-time) extended systems interacting with a (space-time) extended wave. In the case of pulsar timing arrays the detector size is of order the pulsar-Earth distance, which is in excess of 1~Kpc for over half the pulsars in the International Pulsar Timing Array (IPTA). For a gravitational wave point source the radiation wavefront curvature, associated with the finite source-Earth distance, leads to timing corrections of magnitude $(h/f)\sin(\pi{}fL^2/R)$, where $h$ is the gravitational wave strain amplitude, $L$ the pulsar-Earth distance, $R$ the source-Earth distance, and $f$ the characteristic gravitational wave frequency. The timing precision of the best IPTA pulsars are better than 100~ns~rms; correspondingly pulsar timing array observations should be capable of measuring the timing parallax distance to point gravitational wave sources at cosmological distances. [Preview Abstract] |
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W1.00015: Structural characterizations of sputtered nanocrystalline TiN films for electrodes of AMTEC systems M.G. Han, S.-Y. Chun TiN films have been widely used in the tooling industry as a wear resistant coating due to the high hardness and high wear resistance for many years. Recently, TiN films were also used as an important electrode material for the design of alkali metal thermal-to-electric conversion (AMTEC) system due to its excellent electrical conductivity and excellent adhesion layer performance. The control of microstructural characteristics such as grain size, shape, textures, porosity, density, and packing factor are vital for ensuring the reliability of TiN films in structural and functional applications. Nanocrystalline TiN thin films were deposited on Si(100) substrates under various bias voltages have been prepared by a reactive magnetron sputtering. The effect of bias voltage on the microstructural morphologies of the TiN films was characterized by FE-SEM and AFM. The crystallographic texture of the TiN films was characterized by XRD. The films deposited under an Ar + N$_{2}$ atmosphere exhibited a mixed (200)-(111) orientation with a strong (200) texture, which subsequently changed to a strong (111) texture with increasing bias voltage. It is also observed that the crystallite size decreases with increasing bias voltage, which corresponds to the increasing diffraction peak width of XRD patterns. The changes in texture and crystallite size in the TiN thin films are due to one or a combination of factors such as strain energy, surface free energy, surface diffusivity and adatom mobility; the influence of each factor depends on the processing conditions. [Preview Abstract] |
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W1.00016: High resolution $\Lambda $ spectroscopy in Jefferson Laboratory via (e,e'K$^{+})$ reaction Pavlo Baturin The E01-011* (HKS) experiment was conducted in the Fall 2005 at Jefferson Laboratory, Hall-C. It employed a 1.8 GeV, high intensity, quasi-continuous electron beam to produce high resolution spectroscopy of exotic neutron rich $\Lambda $ hypernuclei via associated K electroproduction mechanism, $^{A}$Z(e,e'K$^{+})^{A}$(Z-1)$_{\Lambda }$. The experiment utilized $^{6,7}$Li, $^{9}$Be, $^{10}$B, $^{28}$Si targets for spectroscopy analysis and $^{51}$V, $^{89}$Y, $^{208}$Pb targets for rate studies. The newly introduced tilt method of the electron spectrometer (ENGE) in combination with a brand new high resolution hadron spectrometer (HKS) significantly increased kaon yield and reduced the background rates associated with Bremsstrahlung and Moller scattering. Such kinematics together with the low momentum transfer to $\Lambda $ and a forward angle of recoil electrons, allowed achieving high kaon rates, comparable with mesonic reactions. It also resulted in energy resolution of approximately 400-500 keV (FWHM), an unprecedented value in hypernuclear reaction spectroscopy. This presentation will give a general description of the experiment and will show preliminary results. * This work was in part supported by DoE ER41047 {\&} ER41065 and MEXT, Japan. [Preview Abstract] |
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W1.00017: An Applied Physicist Does Econometrics L.G. Taff The biggest problem those attempting to understand econometric data, via modeling, have is that economics has no \textbf{F }= m\textbf{a}. Without a theoretical underpinning, econometricians have no way to build a good model to fit observations to. Physicists do, and when \textbf{F} = m\textbf{a} failed, we knew it. Still desiring to comprehend econometric data, applied economists turn to mis-applying probability theory---especially with regard to the assumptions concerning random errors---and choosing extremely simplistic analytical formulations of inter-relationships. This introduces model bias to an unknown degree. An applied physicist, used to having to match observations to a numerical or analytical model with a firm theoretical basis, modify the model, re-perform the analysis, and then know why, and when, to delete ``outliers'', is at a considerable advantage when quantitatively analyzing econometric data. I treat two cases. One is to determine the household density distribution of total assets, annual income, age, level of education, race, and marital status. Each of these ``independent'' variables is highly correlated with every other but only current annual income and level of education follow a linear relationship. The other is to discover the functional dependence of total assets on the distribution of assets: total assets has an amazingly tight power law dependence on a quadratic function of portfolio composition. Who knew? [Preview Abstract] |
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W1.00018: Nuclear Medical Science Officers: Army Health Physicists Serving and Defending Their Country Around the Globe Mark Melanson, William Bosley, Jodi Santiago, Daniel Hamilton Tracing their distinguished history back to the Manhattan Project that developed the world's first atomic bomb, the Nuclear Medical Science Officers are the Army's experts on radiation and its health effects. Serving around the globe, these commissioned Army officers serve as military health physicists that ensure the protection of Soldiers and those they defend against all sources of radiation, military and civilian. This poster will highlight the various roles and responsibilities that Nuclear Medical Science Officers fill in defense of the Nation. Areas where these officers serve include medical health physics, deployment health physics, homeland defense, emergency response, radiation dosimetry, radiation research and training, along with support to the Army's corporate radiation safety program and international collaborations. The poster will also share some of the unique military sources of radiation such as depleted uranium, which is used as an anti-armor munition and in armor plating because of its unique metallurgic properties. [Preview Abstract] |
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W1.00019: Studies of final-state photon radiation and mixed EW + QCD higher-order corrections in the process $p\,p,\,p\bar{p}\rightarrow W^\pm \rightarrow \ell^\pm\nu$ Catherine Bernaciak Work has been done to extend the Monte Carlo program WGRAD2$^{12}$, which includes the complete ${\cal O}(\alpha)$ electroweak (EW) radiative corrections to $p\,p,\,p\bar{p}\rightarrow W^\pm \rightarrow \ell^\pm\nu$ to include multiple, soft, final-state photon radiation (mFSR) from a final state lepton as well as initial state QCD corrections up to ${\cal O}(\alpha_s)$. Final state multiple photon radiation is implemented via the QED structure function approach. In this way we study the combined effects of EW and QCD higher-order corrections to this process. In addition to mFSR and QCD NLO corrections, we discuss plans to model initial-state parton shower effects using the POWHEG$^3$ parton shower generator. With WGRAD3 one could then study effects on the W boson mass and other observables due to mixed EW + QCD corrections up to NNLO, initial-state parton showering and final-state multiple, soft photon radiation. \vspace{.53em}\\ $^1$U.Baur, S.Keller, D.Wackeroth, Phys. Rev. D59, 013002 (1999)\\ $^2$U.Baur, D.Wackeroth, Phys. Rev. D70, 073015 (2004)\\ $^3$P.Nason, JHEP 0411 (2004) 040, [arXiv:hep-ph/0409146] [Preview Abstract] |
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W1.00020: Python Graphical User Interface (GUI) for Control of the Levitated Dipole Experiment David Jacome, Darren Garnier, Paul Woskov, Jay Kesner The Levitated Dipole Experiment (LDX) is used to study the confinement properties of plasmas in a magnetic dipole field. In LDX a superconducting coil is levitated for up to 3 hours within a large vacuum chamber to produce the confining dipole field. The plasma experiments take place during this time, with \textit{$\sim $ }10 second plasma shots, one shot every \textit{$\sim $ }5 min. MDSplus software is used to run the experiment and store the data. The software is currently controlled by command line operations. Since levitation time is limited, it's important to maximize efficiency and accuracy of experimental operations. Here, we present a Graphical User Interface (GUI) to efficiently control the operation of the experiment. The need for a GUI that integrates the MDSplus data cycle, cell access control, and routine experimental parameter controls is necessary. The GUI program provides a simple method for monitoring and setting experiment parameters. Python is used as the primary language to run the commands. A program called XRCed distributed by wxPython works as a visual tool. [Preview Abstract] |
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W1.00021: A Cryogenic Torsion Balance for Tests of the Equivalence Principle Frank Fleischer, Eric Adelberger, Massimo Bassan, Blayne Heckel Almost all theories of physics ``beyond the standard model'' predict the existence of new, weak interactions that violate the equivalence principle (EP) at some level. Consequently, precise tests of the EP are a sensitive probe for new physics. The best limits on EP violations currently come from torsion balance experiments, where the dominant contribution to the error budgets are due to thermal noise. To achieve a higher sensitivity to extremely weak forces, we have built a cryostat designed to operate a torsion balance near liquid helium temperature. For cooling, we employ a commercially available pulse tube cooler. The extreme sensitivity of torsion balances to seismic noise required special attention to isolating the vibrations of the pulse-tube cooler from the torsion balance. Results from first tests of the noise performance of the apparatus will be presented. [Preview Abstract] |
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W1.00022: Might Dark Matter and Energy be Intrinsic Properties of Space? Ronald Bruner It is shown that if a volume element, V, of space is assumed to have intrinsic energy E, then consistency of the work-energy theorem with special relativity leads to the equation of state (EOS): E=pV, where p is the pressure of space. When this EOS is incorporated in the Einstein equations it leads to the prediction that the orbital speed of matter circling a galaxy should be relativistic, in disagreement with observations. It is then argued that the mathematical structure of thermodynamics suggests pressure would more naturally be defined as the positive partial derivative of E with respect to V, in which case special relativity leads to the EOS: E=-pV. However, this EOS is also unable to account for observed rotational velocity curves of matter orbiting visible galaxies. Therefore, the possibility that that space has two distinct components of energy is investigated. This results in a plausible two-component EOS in which the former EOS is identified with the dark matter (DM) and the latter with the dark energy (DE). The effective EOS of space may then be written in the form: p=we, where e is the total energy density, p the total pressure, and w represents the fractional excess of DM over DE (and so may range from +1 to -1). This EOS is a viable candidate for explaining all observations attributed to both DM and DE. In particular, it predicts the constant rotational velocity curves observed for matter in circular orbits around visible galaxies. [Preview Abstract] |
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W1.00023: OPTODET: Simulation Software for Modeling Optical Photodetectors Bahram Zandi, Dragica Vasileska, Priyalal Wijewarnasuriya In this work, we report the development of a new simulation software specifically designed for modeling optical photodetectors -- OPTODET. The tool self-consistently solves the continuity equations of the electrons and holes with the Poisson equation, to provide information on the magnitude of the photodetector dark current, spectral responsivity and quantum efficiency in the presence of Schockley-Read-Hall, optical Auger generation/recombination mechanisms and light illumination. The tool then calculates the noise equivalent power (NEP) needed for the calculation of the detectivity of the photodetector being investigated. At present, the tool is tailored at modeling of HgCdTe medium wavelength infrared (MWIR) and HgCdTe long wavelength infrared (LWIR) photodetectors, but a larger database of different materials and of different heterostructures will be made available to the users in the near future. These include the reverse bias potential profiles, the reverse saturation current variation with reverse bias and a plot from which the R$_{o}$A product is extracted at zero bias, respectively. The photodetector characteristics are as follows: the alloy composition is x=0.225 at which value HgCdTe is a semiconductor, the n-type region is 10 um thick and has doping of 10$^{15}$ cm$^{-3}$, the p-type region is 0.8 um thick and is doped to 2$\times $10$^{17}$ cm$^{-3}$. [Preview Abstract] |
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W1.00024: The T2K Neutrino Experiment and the ND280 Near Detector Nagesh Kulkarni The T2K long-baseline neutrino oscillation experiment will search for evidence of neutrino flavor change over a distance of 295 km in a high-intensity muon neutrino beam. The primary goal of the T2K experiment is to measure the neutrino mixing parameter $\theta_{13}$. The near detector is located at 280 meters from proton target at the J-PARC facility in Tokai-mura, Japan, and has already started collecting cosmic ray data. This talk describes the T2K experiment and the aspects of the near detector complex. [Preview Abstract] |
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W1.00025: Nonlinear UV Laser Build-up Cavity: An Efficient Design Nicholas Rady Using the concept of the build-up cavity for second harmonic generation to produce 243nm tunable laser light, an innovative cavity is theoretically explored using a 15mm length CLBO crystal. In order to limit the losses of the cavity, the number of effective optical surfaces is kept to only four and the use of a MgF2 crystal is adopted to separate the harmonic and fundamental laser beam from each other. The cavity is shown to have an expected round trip loss of five tenths of a percent or better, resulting in a conversion efficiency greater than 65{\%}. [Preview Abstract] |
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W1.00026: Monte Carlo Neutron Tagging Efficiency for the MiniCLEAN Experiment Lu Feng Neutrons constitute a serious background for dark matter direct detection experiments since they produce elastic nuclear recoil signals indistinguishable from those caused by weakly interacting massive particles (WIMPs). However, unlike WIMPs, neutrons often interact in the detector medium more than once; and we can utilize this property to identify or tag neutron events that fake WIMP signals. Here, we investigate the upper limit on neutron tagging efficiencies with Monte Carlo (MC) truth information. [Preview Abstract] |
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W1.00027: Detecting and Discriminating Gravitational Microlensing in the SuperMACHO Survey Arti Garg The SuperMACHO Project is a 5 year survey to determine the nature of the lens population responsible for the excess gravitational microlensing rate toward the Large Magellanic Cloud observed by the MACHO project. The MACHO results indicate a large population of compact lenses toward the clouds, and the observed lensing rate is consistent with a Milky Way halo comprised of up to $\sim$20\% Massive Compact Halo Objects (MACHO's), dark matter that is most likely baryonic. This work describes the method by which gravitational microlensing is detected in the SuperMACHO survey. Based on the MACHO findings and the SuperMACHO observing strategy and selection criteria, we expect $<10^{-6}$ of the sources monitored to be lensed at any time. Our detection criteria are designed to minimize false positives while preserving a statistically significant detection rate. We provide an overview of the detection criteria. We also discuss the selection criteria used to discriminate between microlensing and other astrophysical transients. [Preview Abstract] |
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W1.00028: Scaling Studies of Laser Proton Acceleration by Radiation Pressure Sail T.C. Liu, G. Dudinkova, Chuan S. Liu, X. Shao, R.Z. Sagdeev We present scaling studies of proton acceleration by short pulse, intense lasers in the region of radiation pressure acceleration of ultra thin foil. By defining the monoenergetic proton as having energy spread less than 10 percent in 2D PIC simulation, we studied the proton mono-energy profile as a function of the laser power and peak intensity, thin foil thickness and target density ratio to critical density. We found that the energy of monoenergetic proton scales linearly with the square root of laser power after fixing the target density ratio to critical density. The Rayleigh-Taylor (R-T) instability plays significant role in increasing the energy spread of accelerated protons. But, there are parameter regimes for instability remediation or suppression. Parameters of interest are for lasers in sub-Peta Watt range and producing quasi energetic protons to 250 Mev and carbon ion to 1 Gev. The simulation results are able to provide experimentalists with suggestion for optimal scaling for laser acceleration of thin foils for instability avoidance and optimal ion acceleration. Possible medical applications of the technology in proton cancer therapy is also discussed. [Preview Abstract] |
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W1.00029: Dirac's Covariant Constraint Dynamics Applied to the Baryon Spectrum Joshua Whitney, Horace Crater A baryon is a hadron containing three quarks in a combination of up, down, strange, charm, or bottom. For prediction of the baryon energy spectrum, a baryon is modeled as a three-body system with the interacting forces coming from a set of two-body potentials that depend on the distance between the quarks, the spin-spin and spin-orbit angular momentum coupling terms, and a tensor term. Techniques and equations are derived from Todorov's work on constraint dynamics and the quasi-potential equation together with Two Body Dirac equations developed by Crater and Van Alstine, and adapted to this specific problem by further use of Sazdjian's N-body constraints dynamics for general confined systems. Baryon spectroscopy results are presented and compared with experiment. Typically, a best fit method is used in the analyses that employ several different algorithms, including a gradient approach, Monte Carlo modeling, and simulated annealing methods. [Preview Abstract] |
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W1.00030: On new phenomena of micro entity from modified double slits experiment Haisheng Liu A modified double slits experiment was implemented. The visibility of interference pattern is clearly shown and which way information is known simultaneously in the same experiment. Several very important conclusions can be derived from the experimental results. 1) The violation of Bohr's Principle of Complementarity(PC), especially the Englert-Greenberger duality relation of P2 + V2 $<$=1. 2) The particle and wave, in the term of quantum theory, are coexisted simultaneously. They are not mutual exclusive as PC. 3). Photon is not only a simple particle showing bright spot in the usual sense, which cause the click on the detector when photon hits on it or photon pass through one of the two slits, but also with something not observed before (invisible field, dark field, pilot wave, or empty wave, whatever you like to call or define it). 4) What we observed is the bright part, the invisible/dark part govern the motion of the bright part, what we call the photon currently. We also believe all of these new properties should be applicable to all other micro entity like electron, atoms, etc according L. de Broglie assumption. All of these properties will assure the quantum theory is incomplete theory and its related properties have to be reconsidered [Preview Abstract] |
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W1.00031: The Connection between Noneuclidean Geometry and Special Relativity in an Expanding Universe Felix T. Smith The homogeneous Lorentz group is also the isometry group of noneuclidean geometry in hyperbolic space, but the connection has not been fully exploited in special relativity. In a 1907 lecture Minkowski recognized that the velocity \textbf{v} in special relativity generates a noneuclidean manifold. He soon showed this to be part of a covariant 4-vector $\textsf {w}=\left( {1-v^2/c^2} \right)^{-1/2}\left( {v_x ,v_y ,v_z ,ic} \right)$, the vector to the 3-surface of a 4-sphere of imaginary radius $ic$ in velocity space. Unable to identify a comparable geometry in position space, he omitted all mention of this velocity symmetry in later publications. Had the Hubble expansion (1927) been known, he could have used the Hubble time $t_H$, a cosmic time variable $t={t_H} +\delta t$, and a position 4-vector $\textsf {s}=\left( {t/t_H} \right)\left( {x,y,z,i\left[ {c^2{t_H} ^2+r^2} \right]^{1/2}} \right)$, an expanding hypersphere of imaginary radius $R\left( t \right)=ict$. The interval between two local events is, to first order, $\Delta r=\left( {\Delta x,\Delta y,\Delta z,ic\Delta t} \right)$. This is the Minkowski 4-vector in differential form, but the source of its imaginary time is identified as the cosmological expansion. An extended Lorentz group follows if the 4-vectors are replaced by tensors of position and velocity. [Preview Abstract] |
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W1.00032: Big-Bang-Gate Cosmic Titanic: Why Aren't Physics Journal's Editors Bringing It To The Center of Scientific Attention Robert Gentry Until now science's greatest debacle occurred when Copernicus exposed Ptolemaic cosmologists' 1300 hundred year-long fraud that it must be true because observations fit theory so well, while they ignored the untested state of its central assumption of Earth centered planetary motion. With much hubris modern physicists are confident this could never happen again, that the integrity of physics journals editors suffices to guarantee that a challenge to the reigning cosmological theory -- big bang cosmology -- would immediately be brought to the center of scientific attention for analysis and discussion. In fact a decade ago it was reported [MPLA 2619 (1997); arXiv:gr-gc/9806061] that, like Ptolemaic cosmology before it, big bang's central assumption that GR expansion effects cause in-flight expansion had never been tested and, further, that experimental testing of it using GR operation of the GPS showed it to be false. This result proves it is impossible for the 2.73 K CBR to be fireball relic radiation. These results were expanded in CERN reports EXT-2003-021;022, but have been uniformly rejected by physics journals, one of which accepted a paper similar to CERN EXT-2003-022, only to reject it a few days later with the admission not to publish it because of fearing reaction of the worldwide physics community. For update on my PRL submission see \underline {http://www.alphacosmos.net}. [Preview Abstract] |
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W1.00033: Multi-messenger Astrophysics with Swift and IceCube Miles Smith, Neil Gehrels, Doug Cowen, John Nousek, Anna Franckowiak, Ignacio Taboada NASA's Swift telescope has greatly enhanced our understanding of violent astrophysical events, especially gamma-ray bursts. While Swift studies the electromagnetic radiation from these events, other observatories are searching for corresponding cosmic rays, gravity waves, and neutrinos. An initiative is underway to utilize the rapid response of Swift to follow up triggers from these multi-messenger observatories. This talk will address the new capabilities required of Swift and will focus on the collaborative effort between the Swift and IceCube collaborations. The IceCube telescope, located at the South Pole, is searching for astrophysical neutrinos through their interactions in the polar ice. In an effort to mitigate background events, IceCube searches for two or more neutrinos in temporal and spatial coincidence. In response, Swift will slew to observe the IceCube trigger region in X-ray and UV. By accumulating data over a number of orbits, Swift will distinguish between steady sources and the afterglow typical of a burst event. In particular, we will be sensitive to burst events that do not produce prompt gamma rays, which are conjectured to be significantly more numerous than gamma-emitting bursts. [Preview Abstract] |
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W1.00034: The Last Element of Mendeleev's Periodic Table Albert Khazan Despite much achievements of the synthesis for super-heavy elements (10 new elements were obtained during the last 25 years), the experts in Mendeleev's Periodic Table have not answered the most fundamental question: where the Table ends? The calculations produced on the basis of Quantum Mechanics (the physical conditions in micro-scales) do not not answer this question till now. In my study of chemical compounds, I focused onto the physical conditions observed in macro-scales (the subjects of the regular physics and chemistry). Thus, the Law of Hyperboles was discovered in the Periodic Table: given any chemical compound, the contents of any element in it (per 1 gram-atom), including the contents of unknown elements, whose atomic masses can be set up arbitrarily, is described by the equation of a equilateral hyperbola Y=K/X. The tops of all the arcs are distributed along a real axis crossing the line Y=1 in the point of abscissa 411.66, which manifests the actual atomic mass of the last (heaviest) element of the Periodic Table: its location is Period 8, Group 1; its atomic mass is 411.66, its number is 155 (Khazan A. Upper Limit in Mendeleev's Periodic Table --- Element No.155. Svenska fysikarkivet, 2009). [Preview Abstract] |
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W1.00035: The T2K $\pi^0$ Detector and Calibration of Novel MPPC Photo Sensors Kieran Ramos Neutrino oscillations have been discovered by atmospheric and solar neutrino experiments, then later confirmed by experiments using neutrinos from accelerators and nuclear reactors. The Tokai to Kamioka (T2K) experiment, a long baseline neutrino oscillation experiment, will measure the neutrino mixing angle $\theta_{13}$ via a $\nu_\mu \rightarrow \nu_e$ appearance search. $\theta_{13}$ is the third mixing angle which parameterizes the mixing between the first and third generation, and has not yet been measured. T2K uses an intense neutrino beam produced at J-PARC in Tokai, Japan, a near detector (ND280) at 280 m, and Super Kamiokande as the far detector at 295 km. $\pi^0$ particles make a large contribution to the $\nu_e$ appearance background. For this reason the scintillator based $\pi^0$ detector, a sub-detector of ND280, will measure the $\pi^0$ background. The $\pi^0$ detector uses novel Multi-pixel Photon Counter (MPPC) photo sensors. MPPCs are pixelized silicon devices with $\sim1$mm$^2$ active area, where each pixel is an avalanche photo diode working in Geiger mode. This poster will describe the $\pi^0$ detector and MPPC calibration. [Preview Abstract] |
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W1.00036: Superhydrophobic surfaces obtained by positive and negative replication of microstructures in PDMS M\'arcio R.S. Oliveira, Maria C.B.S. Salvadori Until today, researchers have based themselves on nature to choose the best morphology for obtaining superhydrophobic surfaces. In this context, the morphology of a number of hydrophobic plants have been replicated in a variety of materials in order to reproduce their water repellency. Presently, the literature has presented microstructures in the form of tower and pin patterns or other morphologies in the form of protrusions. Contrarily, in the surfaces presented here, the structures contain microcavities that are negative replicas of the morphology that has been explored so far in the literature. In this essay, determination of the wettability of microstrucutured surfaces with positive and negative replicas of three geometries: parallelepiped, cylindrical and hexagonal. [Preview Abstract] |
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W1.00037: Upper Limits on GRB Flux from the Fermi Large Area Telescope Eric L. Winter The Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope has observed over a dozen GRBs since launch. This is a small fraction of the total seen at lower gamma-ray energies by the Gamma-ray Burst Monitor (GBM), also on Fermi. We present upper limits on the high-energy fluxes of bright hard-spectrum GRBs which might be expected to be observed by LAT based on an extrapolation of the low energy spectrum to high energies. Possible mechanisms for a deficit of high-energy photons are discussed. [Preview Abstract] |
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