Bulletin of the American Physical Society
2019 Fall Meeting of the APS Division of Nuclear Physics
Volume 64, Number 12
Monday–Thursday, October 14–17, 2019; Crystal City, Virginia
Session SD: Instrumentation III |
Hide Abstracts |
Chair: Olga Cortes Becerra, GWU Room: Salon 4 |
Thursday, October 17, 2019 10:30AM - 10:42AM |
SD.00001: Recent progress in the development of the CHIPTRAP mass spectrometer Nadeesha Gamage, Ramesh Bhandari, Madhawa Horana Gamage, Rachel Sandler, Philip Snoad, Mattew Redshaw At Central Michigan University we are developing a high-precision Penning trap (CHIP-TRAP) for precise mass measurements with stable and long-lived isotopes with application, for example, to neutrino mass determinations with $^{\mathrm{187}}$Re and $^{\mathrm{163}}$Ho. CHIP-TRAP will consist of a pair of hyperbolic precision measurement traps and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced using a laser ablation ion source and a recently commissioned Penning ion trap source. Ions will be transported to the capture trap at low-energy using electrostatic ion optics and identified via FT-ICR techniques; enabling unwanted ion species to be removed. The ion of interest will then be moved to one of the precision measurement traps. The goal is to simultaneously measure the cyclotron frequency of single ions of two different species, each confined in one of the precision measurement traps, resulting in a cancellation of magnetic field fluctuations and a reduction in statistical uncertainty. In this presentation we will report on the design, construction and operation of the ion sources and will discuss the current status of the CHIP-TRAP project including the recent installation and commissioning of the capture trap. [Preview Abstract] |
Thursday, October 17, 2019 10:42AM - 10:54AM |
SD.00002: Deuterated Organic Scintillators for the Absolute Normalization of Gamma Beam Flux Aidan Walsh, Michael Febbraro, Steven Pain The measurement of the absolute photon flux is a challenging task and can contribute to large uncertainties in gamma-ray beam experiments. Currently, flux determination relies on either Compton scattering at low energies or the photodissociation of deuterium at higher energies. The latter method requires the detection of neutrons, which is tied to the uncertainties and inefficiencies of neutron detectors. To reduce these uncertainties it would be desirable to detect the recoil proton rather than the neutron. To accomplish this the source of deuterium must be active. To this extent we are developing deuterated scintillator tiles, for determination of absolute photon flux. Efforts are underway to produce thin tiles in a minimal loss procedure, due to the high cost of the deuterated monomer. Tiles have been successfully produced and their characterization with gamma-ray sources will be presented. Applications toward beam diagnostics for current and upcoming gamma-ray beam facilities will be discussed. [Preview Abstract] |
Thursday, October 17, 2019 10:54AM - 11:06AM |
SD.00003: Report on the performance of a dual-mode inorganic scintillator TLYC Ching-Yen Wu, Jack Henderson TLYC (Tl$_{\mathrm{2}}^{\mathrm{6}}$LiYCl$_{\mathrm{6}}$, $\ge $ 95{\%} $^{\mathrm{6}}$Li, 75.8{\%} $^{\mathrm{35}}$Cl, $\rho \quad =$ 4.5 g/cm$^{\mathrm{3}})$ is a dual-mode inorganic scintillator with the capability to detect both neutrons and $\gamma $ rays with good energy resolution. The $\gamma $-ray energy resolution better than 4{\%} was reported for a crystal size of 1'' x 1''. Unlike most neutron detectors which depend on the time-of-flight technique to determine the energy, TLYC can be sued to measure the neutron energy directly through charged-particle creating reactions on the constituent isotopes. A resolution better than 10{\%} for fast neutrons with energies up to 8 MeV was obtained for the same class of scintillator, CLYC (Cs$_{\mathrm{2}}$LiYCl$_{\mathrm{6}})$, where cesium is replaced by thallium for the molecular formula of TLYC. It opens the door for many applications. A crystal size of 1'' x 1'' is acquired recently and an extensive test is carried out using a $^{\mathrm{252}}$Cf PPAC to characterize the pulse-shape discrimination between neutrons and $\gamma $ rays as well as the energy and timing resolution. The prompt fission neutron and $\gamma $-ray spectra can be measured by TLYC in coincidence with the detection of fission fragments by PPAC. The detector response for both neutrons and $\gamma $ rays can be measured simultaneously using this coincident technique. The characterization of those performances will be presented. [Preview Abstract] |
Thursday, October 17, 2019 11:06AM - 11:18AM |
SD.00004: Neutron-induced fission measurements with the NIFFTE fissionTPC Michael Mendenhall The NIFFTE collaboration's fission time projection chamber (fissionTPC) is a $2 \times 2\pi$ charged particle tracker designed for measuring neutron-induced fission. Detailed 3D track reconstruction for fission products enables evaluation of systematic effects and corresponding uncertainties which are less directly accessible by other measurement techniques. This talk describes measurements of cross-section ratios between $^{238}$U(n,f), $^{235}$U(n,f), and $^{239}$Pu(n,f) reactions, for incident neutron energies from 0.2 to 20\,MeV from a spallation source at the Los Alamos Neutron Science Center. We also discuss exploration of the $^6$Li(n,$\alpha$)t reaction as a complementary reference in actinide cross-section ratio measurements. [Preview Abstract] |
Thursday, October 17, 2019 11:18AM - 11:30AM |
SD.00005: Using timing to improve low-momentum tracking in silicon trackers Spencer Klein Silicon detectors offer many advantages for tracking charged particles -- they provide outstanding position resolution, so they provide unequalled resolution at for high momentum particles. However, the silicon detectors, being solid, induce more multiple scattering than gaseous trackers like TPCs. In this talk, I will explore the use of high-precision (\textasciitilde 10 -30 psec) timing to alleviate the effects of multiple scattering, by measuring directly the path-length that charged particles take between silicon detectors, and from that path length, the particle's curvature. A timing resolution of 30 psec has been demonstrated in silicon detectors, while 10 psec seems achievable in future devices. I will show that the use of timing can significantly improve the momentum resolution for lower momentum particles. This technique may be useful for detectors at a future Electron-Ion Collider. Time permitting, I will also discuss using timing to help reduce track confusion in high-luminosity environments. [Preview Abstract] |
Thursday, October 17, 2019 11:30AM - 11:42AM |
SD.00006: Use of a CeBr$_3$ implantation scintillator in beta-decay studies of rare isotopes B. P. Crider, Y. Xiao, T. H. Ogunbeku, U. Silwal, D. P. Siwakoti, D. C. Smith, S. N. Liddick, K. L. Childers, R. Lewis, B. Longfellow, S. Lyons, A. L. Richard, M. K. Smith, P. Chowdhury, E. Lamere, S. K. Neupane, D. Perez-Loureiro, C. J. Prokop Beta-decay experiments enable studies of many interesting nuclear phenomena, such as shape coexistence near closed-shell nuclei. Shape coexistence describes where states associated with deformed shapes appear at relatively low excitation energy alongside spherical ones and is indicative of the rapid change in structure that can occur with the addition or removal of a few protons or neutrons. The use of a Cerium Bromide (CeBr$_3$) scintillator as an implantation detector for detecting accelerated rare isotopes and subsequent decays to study shape coexistence far from stability provides a number of desirable quantities, namely high light yield, a fast response, and a high density for the stopping of accelerated ions. A thin CeBr$_3$ implantation scintillator coupled to a position-sensitive photomultiplier tube has been utilized in a recent experiment at NSCL in combination with ancillary detection arrays. First results on the characterization and performance of the CeBr$_3$ scintillator will be presented. [Preview Abstract] |
Thursday, October 17, 2019 11:42AM - 11:54AM |
SD.00007: Highlights from the first year of operating the new ATLAS in-flight facility (RAISOR) C. R. Hoffman, C. Dickerson, G. L. Wilson The ATLAS Accelerator facility at Argonne National Laboratory recently completed upgrades to its in-flight radioactive beam capabilities. The new in-flight facility, RAISOR, was designed specifically for the production of in-flight beams through transfer reactions at ideal energies for nuclear structure work, direct reaction studies, and nuclear astrophysics measurements ($\sim$5 - 15~MeV/u). RAISOR is comprised of an achromatic momentum chicane with bookend quadrupole doublets followed by rebunching and sweeper radio-frequency elements. In this way, both a momentum and velocity selection takes place in the identification of desired in-flight beams of interest. Since the RAISOR commissioning in the Fall of 2018, the facility has been used in six different experimental measurements delivering beams from Li up to P. Milestones include the first in-flight beams at new target stations, increases in the production yields and masses by factors of ten and two over the previous facility. Details on the characteristics of the in-flight beams produced and future facility directions will presented in addition to the physics highlights. [Preview Abstract] |
Thursday, October 17, 2019 11:54AM - 12:06PM |
SD.00008: Characterization of an Iridium Based TES Light Detector for Neutrinoless Double Beta Decay Search Jianjie Zhang Reading out both the heat and light signals from the cryogenic calorimeters used in neutrinoless double beta decay search and direct dark matter detection is a powerful way to reject the background events on an event-by-event basis. For this purpose, we are developing a superconducting transition edge sensor (TES) based light detector targeting O(10) eV energy threshold and O(100) $\mu$s response time, to measure the scintillation or Cherenkov light produced in the target material by particle interactions. The light detector is fabricated by patterning an iridium/platinum bilayer TES at room temperature at the center of a two-inch silicon wafer. The superconducting transition temperature of the TES is tuned to achieve the target energy resolution and response time using the proximity effect. We will present the design, fabrication, and static characterization of such detectors, including the measured dependence of the transition temperature on normal metal thickness, electrical and thermal parameters of the TES, and their calorimetric performance. [Preview Abstract] |
Thursday, October 17, 2019 12:06PM - 12:18PM |
SD.00009: Development of a Fast-Spectrum Self-Powered Neutron Detector for use in Sodium-Cooled Fast Reactors Kathleen Goetz, Sacit Cetiner Self-powered neutron detectors (SPND) have been an essential diagnostic tool for intra-core neutron flux mapping in thermal nuclear reactors for more than 45 years [1]. As next-generation reactors are on the horizon, it is imperative to develop diagnostic tools tuned to their faster neutron spectra [2]. For example, the neutron spectrum in sodium-cooled fast reactors peaks around 0.5 MeV [2]. SPNDs are transistor-like detectors that produce an electrical current as a result of neutron-capture reactions within the neutron-sensitive portion of the detector [1]. The current state-of-the-art for SPNDs is optimized for thermal neutron interactions. We will therefore be discussing our efforts to develop fast-spectrum SPNDs sensitive to neutrons with energies approaching 1 MeV. We have performed an in-depth analysis of ENDF neutron-capture cross sections and have identified 5 novel materials that are suitable to make up the neutron-sensitive portion of our detector, all are stable mid-shell nuclei in the region between doubly-magic $^{\mathrm{132}}$Sn and $^{\mathrm{208}}$Pb. We will also be discussing the results of Geant4 simulations with the chosen materials as well as detector optimization and the exploration of complex detector geometries. [1] Todt, W. H. "Characteristics of self-powered neutron detectors used in power reactors."~\textit{Core Instrumentation and Core Assessment, Nuclear Energy Agency, Boulogne-Billancourt, France}~(1996). [2] Verma, Vasudha, et al. "Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors."~\textit{NIM A: }860 (2017): 6-12. [Preview Abstract] |
Thursday, October 17, 2019 12:18PM - 12:30PM |
SD.00010: Performance of the Neutron dEtector with Xn Tracking (NEXT) prototype. Shree Neupane, Joseph Heideman, David Perez-Loureiro, Robert Grzywacz, Cory Thornsberry, Lawrence Heilbronn, Kyle Schmitt, Mustafa Rajabali, Cole Howell, Leonard Mostella, Joseph Owens, Erin Peters, Anthony Ramirez, Steven Yates, Keith Vaigneur Recent developments in radioactive ion-beam facilities allow the production of very neutron-rich nuclei. Away from the line of beta stability towards neutron-rich nuclei, $\beta$-delayed neutron emission is the dominant decay mode. Neutron dEtector with Xn Tracking (NEXT) has been designed to better measure $\beta-$delayed neutron energies. By segmenting the detector along the neutron flight path, NEXT will reduce the associated uncertainties in neutron time-of-flight measurement, improve energy resolution while maintaining detection efficiency. A detector prototype has been built using segments of plastic scintillator with n-$\gamma$ discrimination coupled to position sensitive photomultiplier tubes. The results from the proof-of-principle measurements using a $^{252}$Cf neutron source and accelerator-produced mono-energetic neutrons will be presented. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700