Bulletin of the American Physical Society
Annual Meeting of the Four Corners Section of the APS
Volume 57, Number 11
Friday–Saturday, October 26–27, 2012; Socorro, New Mexico
Session E5: Nuclear Physics I |
Hide Abstracts |
Chair: Mark Boslough, Sandia National Laboratories Room: Macey Center Agora |
Friday, October 26, 2012 4:30PM - 4:42PM |
E5.00001: Transit-time Mapping of Photomultiplier Tubes Nirdosh Chapagain, J. Bart Czirr, Lawrence B. Rees, Michael J. Ware Photomultiplier tubes are used in various experiments in conjunction with scintillators to detect ionizing radiation. BYU nuclear physics group has been using different models of photomultiplier tubes for their neutron detection research. Motivated by the neutron detection experiments at BYU we have developed an experimental setup to map the transit-time difference and intensity difference as a function of the position of the photocathode illumination. I will present an overview of the set-up and preliminary results for an ADIT (B133D01S) photomultiplier tube. The accurate understanding of the transit-time difference is very useful for neutron time of flight experiments. [Preview Abstract] |
Friday, October 26, 2012 4:42PM - 4:54PM |
E5.00002: LGB neutron detector Nicole Quist The double pulse signature of the Gadolinium Lithium Borate Cerium doped plastic detector suggests its effectiveness for analyzing neutrons while providing gamma ray insensitivity. To better understand this detector, a californium gamma/neutron time of flight facility was constructed in our lab. Reported here are efforts to understand the properties and applications of the LGB detector with regards to neutron spectroscopy. [Preview Abstract] |
Friday, October 26, 2012 4:54PM - 5:06PM |
E5.00003: Resilience of Double Tube Hybrid Neutron Detectors Trevor Jex Both cadmium and lithium-glass are excellent neutron-detecting materials. However, the combination of these two materials in one detector has the possibility of even further enhancing the efficiency and effectiveness of a single detector. Such advances present an opportunity to eventually increase the effectiveness of neutron detectors at US borders detecting illicit nuclear material. Though the research is still in infancy and requires further substantiation, the possibilities of increased detection efficiency as well as the knowledge gained about detection geometry and data analysis far outweigh any challenges. [Preview Abstract] |
Friday, October 26, 2012 5:06PM - 5:18PM |
E5.00004: A multi-purpose robotic sample changer for texture and powder measurements on the HIPPO neutron diffractometer Adrian Losko, Sven Vogel Automation of sample changes is essential on neutron diffractometers with short count times per sample (as little as 1min for steel samples), such as the high pressure preferred orientation (HIPPO) instrument at the Los Alamos Neutron Science Center (LANSCE), to allow for a high sample throughput. Efficient use of available neutron flux is indispensable and reduces the instrument downtime and workload of beamline personnel. High precision motion in cartesian coordinates permits accurate sample alignment and increased coverage of sample directions for texture measurements. Using geometrical properties of diffraction by crystals, corrections in sample displacements in strain measurements will minimize the artificial strain due to misalignment of the sample position to determine the center of ``gravity'' of the diffraction signal by utilizing a sample rotation that will ensure that the same grain population will diffract in two different detectors, allowing to determine any sample position offset. Those corrections are only achievable with a combination of high precision sample positioning and a large detector coverage as on HIPPO. Here we present the capabilities of the new robotic sample changer to help improve texture and strain measurements on the HIPPO instrument. [Preview Abstract] |
Friday, October 26, 2012 5:18PM - 5:42PM |
E5.00005: Inertial Confinement Fusion at the NIF - What we learn from imaging of neutrons coming from the burn region Invited Speaker: Nevzat Guler Inertial Confinement Fusion experiments at the National Ignition Facility (NIF) are designed to understand and test the basic principles of self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic (CH) capsules. The experimental campaign is ongoing to tune the implosions and characterization of burning plasma conditions. Nuclear diagnostics play an important role in measuring the characteristics of these burning plasmas, providing feedback to improve the implosion dynamics. I will present the data collected with the recently commissioned Neutron Imaging (NI) diagnostic that provides vital information on the distribution of the central fusion reaction region and the surrounding DT fuel. These fuel distributions are measured through neutron images collected at two different energy bands for primary (13-17 MeV) and downscattered (6-12 MeV) neutrons. From these distributions, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. In addition, the spatially averaged density of the nuclear fuel, another important parameter for optimizing and understanding the ignition conditions, can be calculated from these images during the peak neutron emission time. [Preview Abstract] |
Friday, October 26, 2012 5:42PM - 5:54PM |
E5.00006: Modeling nuclear explosion Jeremy Redd, Alexander Panin As a result of the Nuclear Test Ban Treaty, no nuclear explosion tests have been performed by the US since 1992. This appreciably limits valuable experimental data needed for improvement of existing weapons and development of new ones, as well as for use of nuclear devices in non-military applications (such as making underground oil reservoirs or compressed air energy storages). This in turn increases the value of numerical modeling of nuclear explosions and of their effects on the environment. We develop numerical codes simulating fission chain reactions in a supercritical U and Pu core and the dynamics of the subsequent expansion of generated hot plasma in order to better understand the impact of such explosions on their surroundings. The results of our simulations (of both above ground and underground explosions) of various energy yields are 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