Bulletin of the American Physical Society
2019 Joint Fall Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 64, Number 18
Friday–Saturday, October 25–26, 2019; Lubbock, Texas
Session B04: SPS I |
Hide Abstracts |
Chair: Toni Sauncy, Texas Lutheran University Room: Student Union Building Playa Room |
Friday, October 25, 2019 10:21AM - 10:33AM |
B04.00001: Muon Tomography Model for Monte Carlo Simulation of Prototype Muon Telescope Raul Perez, Sadman Shanto, Samuel Cano, Shuichi Kunori, Nural Akchurin, Mohammad Moosajee, Cristobal Moreno We aim to develop a portable muon detector with an excellent spatial resolution that will be able to image large structures in great detail. Muons are elementary particles that pass through matter, losing energy in the process. Muon tomography is a technique that exploits this phenomenon to construct images of large objects of interest. Our experiment involves the detection of a water tower and its contents using the prototype detector. A Monte Carlo (MC) Simulation was developed to improve our detector. The present MC Simulation utilizes GEANT4 combined with Cosmic-ray Shower Library (CRY) and ROOT for data analysis. CRY is being used to generate muons with an angular distribution and an energy spectrum corresponding to those of cosmic ray muons at sea level. GEANT4 is used for simulating the geometry of our detector/water tower, tracking muons, and monitoring their interactions with the geometry's material. The necessary information required for muon analysis are stored as ntuple files, which we use to analyze the muon density detected for different configurations of our geometry and construct 1D and 2D muon projections of the tower showing its contents. In an effort to improve our prototype we are comparing the simulated results with our experimental results. [Preview Abstract] |
Friday, October 25, 2019 10:33AM - 10:45AM |
B04.00002: A computer is any machine that quantifies natural phenomena in order to simulate abstract mathematical functions. There are two main paradigms for computers: analog and digital. Digital computers use step-wise properties of nature to simulate discreet mathematics. This is opposed to the earlier analog co Troy Long, Eddie Holik A computer is a machine that quantifies natural phenomena to simulate mathematical functions. There are two paradigms for computers: analog and digital. Digital computers that use relative extremes to simulate discreet mathematics. Analog computers implement continuous natural properties to replicate continuous functions. Analog optical computing has the potential to transfer information rapidly, using atomic emissions as an optical transistor. Optical equipment was used in order to demonstrate one way light can be used to produce calculations. A laser was used to reflect a beam of light off a mirror mounted to a piezo-electric crystal element, creating a simple optical transistor. When a voltage is applied across a piezo element, it mechanically expands. By placing the piezo element under the mirror like a shim and applying different voltages, the normal line between the mirror and the beam shifted, causing the beam to repeatably reflect to different locations on a screen. Using a photo-detector, numerical values can be taken from the intensity of the light shining on the detector. The presentation will include the design process for creating the piezo-electric optical demonstrator, for the purpose of encouraging creative, critical thinking in new fields of computer development. [Preview Abstract] |
Friday, October 25, 2019 10:45AM - 10:57AM |
B04.00003: Developing a Python-based Computational Model for Photoluminescence from a single, strained InGaAs/GaAs Quantum Well. Johari Dramiga, Toni Sauncy An empirically obtained relationship, the Varshni Equation, has been successfully used to model the temperature dependence of photoluminescence for most bulk semiconductor materials. However, for quantum wells, the model does not show good agreement with observations in many cases. Using python, the photoluminescence emission of a single, strained InxGa1- xAs/GaAs quantum well has been modeled. The model accounts for variations in x (In mole fraction) in the alloy material, and differences in the temperature dependence of the lattice constant in each material, to determine the compressive strain present in the well layer. First order elastic theory is used to understand the role of that strain on the InxGa1-xAs band structure. Vegard's Law was used to interpolate material parameters for the InxGa1-xAs alloy. Standard finite square well solutions are used to determine quantum confinement within the well to determine initial and final electron transition states and includes temperature dependence of the barrier and well band gaps. The model then loops through temperature steps to produce a model of the PL emission as a function of temperature. The model output was compared to experimental data for several well widths and In mole fraction and has successfully demonstrated observed subtleties in the low temperature (\textless 30K) temperature range. [Preview Abstract] |
Friday, October 25, 2019 10:57AM - 11:09AM |
B04.00004: Emergence of Quantum Chaos in a Model 4-Body System Cooper Johnson, Nirav Mehta We implement the method of ``slow variable discretization'' (SVD) to solve the Schrodinger equation for the (quasi)-bound state energy levels of a system of four interacting atoms moving in one spatial dimension. The SVD method we implement treats the hyper-radius (a measure of the overall size of the system) as a ``slowly varying'' parameter. This parameter can then be discretized using the ``discrete variable representation'' (DVR) technique, which guarantees our numerical approximations will converge to being exact given a large enough basis size. To measure chaos, we appeal to the Bohigas, Giannoni, and Schmidt conjecture, which states a classically chaotic system can be statistically described by random matrix theory in quantum mechanics, where random matrix theory makes predictions for the nearest neighbor energy level spacings. We calculate the distribution of energy-level spacings and fit it to the Brody distribution to extract a Brody parameter. A calculation in the adiabatic hyperspherical representation in which all nonadiabatic couplings are ignored gives a perfectly Poisson distribution, corresponding to a Brody parameter of zero. A calculation with SVD, on the other hand, which implicitly incorporates nonadiabatic couplings, yields a Brody parameter of 0.571, indicating a sizable degree of level repulsion characteristic of the transition from an uncorrelated system to one with chaos. [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