Bulletin of the American Physical Society
86th Annual Meeting of the APS Southeastern Section
Volume 64, Number 19
Thursday–Saturday, November 7–9, 2019; Wrightsville Beach, North Carolina
Session D04: Poster Session (6:00pm - 7:30pm) |
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Chair: Mohammad Ahmed, North Carolina Central University Room: Holiday Inn Resort Prefunction Concourse |
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D04.00001: Dependence of Johnson Noise on Resistance and Noise Density R. Seth Smith, Chace Covington Johnson noise is electronic noise generated from a nonzero emf in resistors due to a thermodynamic connection between heat dissipation and fluctuations. While the average emf in resistors is zero, the value fluctuates around zero, creating noise that interferes with signals that one can measure from the circuit. A TeachSpin Noise Fundamentals apparatus was used to measure Johnson noise and explore its characteristics. Johnson noise was analyzed as a function of resistance by inserting different resistances into a circuit. By adjusting the bandwidth of an electrical signal, Johnson noise was also analyzed as a function of noise density and the results were used to measure a value for Boltzmann's constant. The experimental setup will be described, and the results will be presented. [Preview Abstract] |
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D04.00002: Effect of Argon flow and DC bias on optical emission spectroscopy of Argon/Hydrogen plasmas. Bhavesh Ramkorun, Kallol Chakrabarty, Shane Catledge Microwave plasma chemical vapor deposition (MPCVD) processes often make use of hydrogen and argon in the feedgas mixture. Ions in the plasma bombard the growing materials surface and can affect sp2/sp3 molecular bonding configurations (such as synthesized in hexagonal/cubic boron nitride coatings). In this study, we investigate the effect of DC bias on a silicon substrate, using optical emission of hydrogen plasmas containing a range of argon flow rates. Microwave power and chamber pressure were held fixed at 0.6kW and 10Torr, respectively. Optical emission spectroscopy (OES) was used to analyze intensity from select emission lines of hydrogen (434 nm, 486 nm, and 656 nm) as well as from argon (696 nm, 706nm, and 763nm). Our results indicate that the intensity of argon increases linearly as flow rate of argon increases. The intensity of argon is also independent on the bias voltage of the substrate between --100 V and --260 V. The intensity of hydrogen remains constant when flow rate of argon changes from 0 sccm to 200 sccm. However, when the flow rate of argon changes from 300 sccm to 500 sccm, the intensity of hydrogen increases with bias voltage from -- 100V to -260 V. These results may be used to correlate plasma emission characteristics based on substrate bias conditions with coating structure/properties in order to better predict and control MPCVD-grown materials. [Preview Abstract] |
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D04.00003: Optimization of the Travelling Salesman Problem via Algorithms based on Physical Phenomena Jacob Glidewell, Wei-Chih Chen, Chia-Min Lin, Cheng-Chien Chen Numerical optimization concerns finding the minima of a specific mathematical object to certain parameters. A powerful optimization technique has limitless applications in every science and engineering field. In this research, we investigate the application of various optimization algorithms to the Travelling Salesman Problem (TSP): Given a salesman and N cities, what is the shortest path the salesman can take such that he/she visits all N cities exactly once and returns to the starting city? TSP is an NP-hard problem, where its solution cannot be computed in a polynomial time or simply, very ``quick''. With this, optimization algorithms can be used to find or approximate the best solution. We use two simple algorithms -- Nearest Neighbor and Two Opt-- along with three more complicated algorithms -- Simulated Annealing, Genetic Algorithm, and Particle Swarm Optimization -- which are all based on physical or natural principles. We conclude that the three complex algorithms are much more efficient; however, the two simpler ones still provide a useful path length reduction although without a complete optimization. The results can be applied to other more complicated optimization problems such as crystal structure prediction with a complex energy landscape. [Preview Abstract] |
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D04.00004: Electron Motion near Defects in Solar Cells Aidan Edmondson, Tim Gfroerer, Fan Zhang, Yong Zhang Most solar cells are made of crystalline materials that contain a variety of defects, which form during crystal growth. These defects reduce the efficiency of the device because defective regions allow energy to be lost as heat. Normally, the electron-hole pairs that are created when sunlight hits the solar cell generate current. But these pairs can be drawn into defects where they produce heat instead. We study the effects of defects in GaAsP semiconductors with and without doped conductive layers. By stimulating the samples with unfocused laser light, we can analyze the influence of defects as a function of illumination and temperature. We also use laser mapping to investigate the behavior under focused illumination. Our work shows two effects. First, electrons move differently in the presence of conductive layers, indicating that a different diffusion model is required for solar cell devices. Second, defect-related losses operate differently when we switch between the unfocused and focused illumination experiments. [Preview Abstract] |
(Author Not Attending)
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D04.00005: Assessment of Alternative Approaches to Source Reconstruction Using Solid State Dosimetry Ryan O'Mara, Robert Hayes Recent advancements in luminescence and electron spin resonance dosimetry have made it possible to measure radiological exposures to nearly every insulating material in the developed world. By measuring populations of unpaired charges in the material, these techniques can probe the electronic population distributions caused by ionizing radiation exposure. Previous analyses have shown that luminescence dosimetry can be used to localize and assay radioactive materials after that material has been removed. Traditionally assaying historical radiation sources has involved coupling measured dose deposition profiles with computationally expensive particle transport calculations. Our analysis will attempt to determine the extent to which these full transport calculations can be replaced with analytical equations that account only for geometric and material attenuation while providing adequate accuracy. The goal of this analysis was to determine the bounds in which such analytical simplifications can be used to develop a correction function approach to account for the additional physical processes without requiring iterative Monte Carlo type approaches. [Preview Abstract] |
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D04.00006: Measuring the Magnetic Moment of a Magnetic Dipole James Morris, Sethfield Smith The purpose of these experiments is to investigate the interaction of a magnetic dipole moment with a magnetic field. Five experiments were conducted to measure the magnetic moment of a magnetic dipole, including Balancing Magnetic Torque and Gravitational Torque, Harmonic Oscillation of a Spherical Pendulum, Preccessional Motion of a Spinning Sphere, Net Force in a Magnetic Field Gradient Using the Magnetic Force Balance, and Determining the Magnetic Moment from the 1/r$^{\mathrm{3}}$ Dependence of the Magnetic Field Along the axis of a Magnetic Dipole. The experimental setups and results will be presented and compared for each of the five experiments. [Preview Abstract] |
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D04.00007: Detecting Corrosion in Steel Canisters using Deep Learning Preston Robinette, Hayley Guy, Bryce Kroencke, Jordan Miller, Daniel Schultz, Catherine Schuman, Stylianos Chatzidakis, Jacob Hinkle, Theodore Papamarkou, Laura Pullum, Guannan Zhang Steel canisters are typically used to store spent fuel from nuclear reactors after the rods have been cooled down in spent fuel pools. The lack of a permanent repository necessitates the use of these canisters for longer periods of time than initially anticipated, resulting in concerns of potential aging. Fast and accurate, nondestructive inspections are therefore needed to ensure the longevity of canister integrity and reduce potential mitigation and remediation costs. High radiation levels, limited access (via small size vents), and space constraints (2-inch overpack-canister gap) make in-situ visual inspections challenging. This necessitates the development of remotely operated systems for real-time detection of defect properties. In order to create an automated system, the project explores, for the first time, the use of convolutional neural networks (CNNs) to accurately detect cracking and pitting in real time. Trained on 22,215 images of 256 x 256 pixel resolution, the preliminary results are promising with achieved accuracies up to 96{\%}. The proposed approach could significantly increase the speed of inspections, minimize inspection costs, and minimize radiation doses to personnel. [Preview Abstract] |
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D04.00008: Study on the Forces acting a Rocket to Predict its Trajectories Using Aerodynamics Yejin Chung, Richard Kyung The trajectories of a rocket result from different forces acting on it. Kinematics and Newton’s three laws of motion provide understanding of the rocket’s motion upon the launch. The flow of air is critical in the resulting curve; as air moves in one direction, the rocket has to go in the opposite direction. For instance, if the air is slowing down on the right side, a buildup of air creates a higher pressure differential on the right side which pushes the rocket to the left. The forces acting on a rocket in flight are weight, lift, drag and thrust which are the main aerodynamic factors on the rocket. Drag and thrust are two important components of aerodynamic force. In this paper, the magnitude of the forces were studied by changing the factors. The trajectories of a rocket and its motions were studied by changing the values of the factors that affect the forces such as lift, thrust and drag. Also this paper examines the kinematics to decide its motions and also calculation of major forces on the rocket was performed. Accelerations, flight distances, velocities, and other dynamic characteristics were calculated as a function of time. [Preview Abstract] |
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D04.00009: Low Frequency Plasma Instabilities and Flow S Sen, Taylor Smith, Patrick Adegbaye, Jina Walls, Mia Chaneice, Iman Mombo We study the effect of low-frequency plasma instabilities in the presence of inhomogeneous plasma flow and the result is applied in to explain various atmospheric and space plasma disturbances and turbulence. Remarkable similarities are discovered. [Preview Abstract] |
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D04.00010: Understanding Shear Thinning using Brownian Dynamic Simulations Mackenzie Wall, Luis Sanchez-Diaz In this work, we study the changes in structure during the shear-thinning regime using Brownian Dynamics with a simple steady-state shear flow of binary charged colloidal suspension. Previous research has shown that the decreasing viscosity is the result of layer formation; however, there are fluids whose viscosity does decrease, but lacks the layer formation. With our Brownian Dynamic Simulation, we were able to reproduce the results obtained in a recent rheo-SANS experiment and we also explored at what conditions layer and non-layer formation occurs from at different parameters. [Preview Abstract] |
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D04.00011: The influence of sea ice melt on phytoplankton spring bloom dynamics in Fram Strait. Conner Lester Springtime in Fram Strait is marked by intensive large-scale phytoplankton blooms that are crucially seeded and sustained by sea ice melt. While the close connection between sea ice melt and plankton blooms is well established, important open questions remain regarding the mechanistic relationships linking~the release of meltwater and physical and chemical upper ocean variability to the growth, community composition, and carbon uptake of lower trophic levels. In this study, we examine satellite-derived sea ice and surface chl-a data, in concert with in situ measurements collected during an oceanographic cruise in May 2019, to quantify relationships between spatial and temporal characteristics of spring blooms and the sea ice cover. Satellite observations document a strong ice-edge bloom in May 2019, with maximum chl-a concentrations reaching near 10 mg m-3. High resolution ocean color and SST imagery from Landsat exhibit strong submesoscale activity at the ice edge, with eddies and fronts leading to strong gradients in surface properties. Sea ice edge conditions are marked by high variability, ranging from a packed, clearly defined ice edge, to diffusely spread ice floes and filament-like bands of sea ice. Comparison of satellite-derived chl-a concentrations with output from an idealized phytoplankton growth model forced by observed sea ice concentrations yields further insight into the relationships linking physical processes to biological response. Due to the hierarchical importance of phytoplankton blooms for a thriving ecosystem in Fram Strait, it is crucial to understand how their dynamics vary with the current and imminent variations in Arctic sea ice conditions. [Preview Abstract] |
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D04.00012: High Resolution Tagger Hodoscope . Wolfgang Irrig An intensity, high resolution tagged photon beam is critical for the highly rated experiments in Hall D at Jefferson Lab, such as the GlueX experiment and PrimEx-eta experiment. It is produced by a high energy electron beam off a thin radiator. The energies of resulting photons are measured by a Broadband Tagger Hodoscope (TAGH) with a dipole magnet. I tested and repaired the TAGH counters as my summer research project. The procedure and the result of this work will be reported. [Preview Abstract] |
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D04.00013: The status of the ultra-high resolution spectroscopy at the HFIR Fankang Li, Jiazhou Shen, Lowell Crow, Qiang Zhang, Feng Ye, Thomas Keller, Olivier Delaire, Roger Pynn, Jaime Fernandez-Baca To measure the crystal lattice distortion or the lifetime of weak interactions among quasiparticles, such as phonons, electrons and magnons, with high resolution, the key is to break the inverse relationship between the resolution and useable flux. By using the Larmor precession of the neutron spin inside a given magnetic field, its momentum or energy change during the interactions with sample can be measured with ultra-high resolution. Therefore, this unique property of neutron provides us with another approach to overcome some of the limitations of conventional neutron scattering instruments. Also, it can make the best use of all the available neutrons by allowing the use of large divergent beams. The progress on upgrading the HB-1 polarized triple axis spectrometer at the High Flux Isotope Reactor of ORNL with superconducting magnetic Wollaston prisms will be presented. For neutron diffraction, the achievable resolution of the absolute peak splitting and relative lattice distortion ($\Delta $d/d) can be 2x10$^{\mathrm{-4}}$ and 1x10$^{\mathrm{-6}}$ relatively. While for inelastic scattering, for example phonon linewidth measurements, the resolution can be \textless 10ueV. [Preview Abstract] |
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D04.00014: Measuring the target polarization for the Jefferson Lab Hall B Polarimeter Katherine Wild, Brian Raue A significant portion of the CLAS12 physics program requires knowledge of the electron beam polarization, which is measured with a M{\o}ller polarimeter. The longitudinal component of the beam polarization is given by $P_{B}^{z}=\frac{A}{{\thinspace A}_{zz}P_{T}^{z}}$, where $A_{zz}$ is the M{\o}ller analyzing power, $P_{T}^{z}$ is the target polarization, and $A$ is the beam-spin asymmetry measured by detecting scattered electrons in coincidence after the beam strikes a polarized permendur target. To find the beam polarization, the polarization of the target must be known. We have used a bench-top apparatus consisting of solenoid coil to generate a polarizing field and a pickup coil surrounding the target material to measure the magnetization of the target when the solenoid field is reversed. In this poster we will present the details of our apparatus and analysis procedure along with results of measurements and the accompanying uncertainties. The total relative uncertainty in the target polarization is $\delta P_{T}^{z}/P_{T}^{z}\approx 0.02$. [Preview Abstract] |
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D04.00015: Lock-In Based Technique for High Sensitivity Probe of Dielectric Modulation Joseph Tolone, Yong Zhang The purpose of this research is to develop a system that can detect weak, modulated signals. When taking measurements that are directly concerned with waves, interference and noise can become problematic. A lock-in amplifier is able to extract accurate information about the signal it is measuring and minimize the noise. By modulating incoming signals with an optical chopper, the lock-in amplifier is able to discriminate between modulated signal and unmodulated noise, and it can selectively amplify only the modulated signal. The development of a data acquisition system that uses a lock-in amplifier, optical chopper, laser/light source, and photo detector interfaced with a computer would improve the efficiency and effectiveness of optical-based measurements. In this research, I attempted to develop a data acquisition system using the format outlined above. At first, the system was synchronized with just the lock-in amplifier, optical chopper and photo detector. After testing and optimizing this system, a computer interface was added to try and provide more control and automation for future experiments. This modulation system will be applied to multiple areas of research and experimentation upon completion. [Preview Abstract] |
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D04.00016: Quantum Ghost Imaging of Intensity and Phase Objects Tikaram Neupane, William Moore, Bagher Tabibi, Felix Seo The quantum ghost imaging of intensity and phase objects were studied with two spatially entangled photon pairs by two spontaneous down conversions in the double Mach-Zehnder interferometers. The spatially entangled photon pair of signal and idler was produced by a pump beam with both momentum and energy conservations. The visible down conversion is called as signal and infrared down conversion is named as idler conventionally. The first infrared is interact with the intensity and phase object and induces the coherency with the second idler without amplification that holds the indistinguishability between idlers. The indistinguishability of idlers in the infrared spectrum provides the interference of signals in the visible spectrum. Then, the interaction of infrared with intensity and phase objects provides the measurement of visible with the nonlocal correlation. [Preview Abstract] |
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D04.00017: Quantum Spooky Lidar of Satellite Constellation Tikaram Neupane, William Moore, Bagher Tabibi, Felix Seo The conventional classic infrared lidars for atmospheric gas sensing have relatively inferior performance in terms of quantum efficiency and dark noise and lost, and requires the higher cost than their visible-range computer-parts. However, the visible measurement with infrared interaction through spatial and temporal nonlocal correlation has relatively lower cost. The quantum spooky lidar with spatial and temporal entanglement does not need an infrared detector and just use widely available single-photon avalanche diodes which offer the optimized sensitivity and signal-to-noise ratio in the visible spectra. In addition, the quantum resolution beyond classic imaging and sensing, secure quantum information without cloning, and interaction-free measurement of atmospheric gases have the significant scientific and technical merits, break new ground of atmospheric sensing and imaging technology. [Preview Abstract] |
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D04.00018: Finding a Material with a Low Energy Threshold for Charged--Current Neutrino Interactions Thomas Richards, Kate Scholberg We calculated the thresholds for charged--current electron neutrino and antineutrino interactions for most of the stable isotopes. Looking at the isotopes with the lowest thresholds, we found that tantalum--181 ($^{181}$Ta) and gadolinium--160 ($^{160}$Gd) are reasonable candidates for low--threshold neutrino detectors, with thresholds at $0.188$ MeV and $0.105$ MeV respectively. These materials are both metals, have relatively high natural abundance, and are not frequently found in conjunction with radioactive substances, making them potentially viable for this task. Using the SNOwGLoBES software library, we computed estimated cross sections and event rates for supernova fluxes in these two materials. [Preview Abstract] |
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D04.00019: Ultra-low energy Fermions as a contributor to dark energy Robert Hayes When any ultra-low energy particle has a wavelength comparable to or greater than the Hubble length, the space between that particles ends overlapping the Hubble length expand at the speed of light and so effectively freeze the particle in place (its trough can never reach the location of its crest). Any such particles are then effectively coupled to the horizon in that they are forced to stretch with the same (tentatively including primordial particles, Hayes 2017). All such particles so coupled to the Hubble length which happen to be Fermions are then also subject to the Pauli exclusion principle (PEP). The antisymmetric nature of any such ultralow energy fermions when coupled to the Hubble length requires them to take distinct quantum numbers including that of spatial location. Any overlap then will result in a force similar to the very familiar terrestrial force of PEP between touching materials to prevent valence electron overlap. This provides a predictable standard model mechanism for large scale cosmological expansion beyond the initial big bang inflationary kinetic energy if the coupling to the Hubble length does not just pull on the Fermions but can also be pushed on by the same. Reference; Hayes RB. (2017) A standard model approach to dark energy and inflation. J. Cosmology 26, pp 14850-14859. [Preview Abstract] |
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D04.00020: Studying the Properties of Diffuse Atomic Halo Gas Surrounding the Milky Way and M83 Pallavi Maladkar, Rongmon Bordoloi Diffuse atomic gas permeating and surrounding galaxies constitutes a large fraction of galactic baryonic mass. When these gas clouds are gravitationally accreted, they can interact with the interstellar medium and contribute significantly to the galactic star formation rate. We focus on determining the spatial extent and kinematics of these gas structures along lines of sight to Messier 83. We employ absorption line spectroscopy and analyze 126 new spectra of pointings oriented inside and surrounding Messier 83. We measure the absorption line strengths and column densities of ionized Ca II gas observed around the Milky Way and Messier 83. We observe several cloud structures present in the region of Messier 83 as well as the Milky Way. We present a preliminary model for the thickness and extent of the cloud assuming constant density. In the future, we look to extend this research to parameterize the accretion rate of the gas structures surrounding Messier 83 and our own galaxy. [Preview Abstract] |
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D04.00021: Supernova Remnants: Galactic Cosmic Ray Accelerators Adam Vendrasco, Jordan Eagle, Marco Ajello Supernova remnants (SNRs) and pulsar wind nebulae (PWNe) are considered to be the most promising candidates for the acceleration of particles to cosmic ray (CR) energies ($\leq10^{15}$,eV). This paper reports the investigation into candidate CR accelerators and their respective counterparts. Very high energy (VHE, E$>$50,GeV) $\gamma$-ray emission is discovered by Fermi-LAT on the western edge of the supernova remnant known as SNR-G344.7-0.1, which is reported in the 2FHL catalog. This source, 2FHL-J1703.4-4145, likely has a TeV counterpart, HESS-J1702-420. The observed gamma-ray emission is a possible byproduct of the interaction between the SNR shock-wave and a molecular gas cloud. We present a summary of supernova remnants as Galactic accelerators and discuss examples. X-ray data reduction and analysis is performed on available X-ray data of SNR-G344.7-0.1 to understand the region overlapping with the 2FHL counterpart. [Preview Abstract] |
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D04.00022: Elastic body motion in General Relativity Nishita Jadoo, J. David Brown We investigate a general relativistic formulation of elastic theory. The elastic body has negligible self-force and moves in a background space time metric. We solve the equations of motion for the case of a compact isotropic elastic body with free surface boundary conditions near a Schwarzschild black hole. We observe the deformations of the elastic body and look at possible deviations of its motion from a geodesic path. [Preview Abstract] |
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D04.00023: Modeling Transition Histories from Inflaton to Radiation Domination Jordan Sheely The period of accelerated expansion in the early Universe known as inflation provides compelling solutions to the horizon and flatness problems, the homogeneity of the Universe, and the source of density fluctuations that go on to seed structure formation. It is widely taken to be driven by a slowly evolving scalar field, the inflaton, that dominated the Universe during inflation. The field then decays into a radiation bath, reheating the Universe. There is little understanding of the Universe's transition from inflaton to radiation domination; in order to learn more about inflation, we need to know information about this transition to link observations back to inflaton dynamics. We explore the mechanics of inflation and reheating in the limit of perturbative decay, and test possible transition histories from inflaton to radiation domination. In the standard picture of inflation, the inflaton experiences decaying oscillations about its minimum, losing all its energy. We examine the possibility of decay so rapid that the inflaton never reaches an oscillatory state, and find that it is mathematically possible. We then find reheating histories for various ratios of the inflaton decay rate $\Gamma$ to its mass $m$ with two fixed reheating temperatures ($10^{10}$ and $10^{15}$ GeV). [Preview Abstract] |
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D04.00024: ABSTRACT WITHDRAWN |
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D04.00025: Developing a laboratory-scale kilonova apparatus Martin Driggers, Matt Meyers, Patrick Johnson, Chad Sosolik Kilonova are currently the predicted source of all elements heavier than iron. Following the recent measurement of light from a kilonova event, emissions spectra from these heavier elements is necessary to verify this theory. We have designed and built an apparatus capable of creating heavy metal ions that emit spectra relevant to kilonova events. This apparatus consists of a vacuum chamber containing a tunable RHEED electron gun and a metal target. The electron gun bombards the target producing ions. The target consists of a box with an entrance port for the electrons and a viewing port to observe the spectra. To test our apparatus, we measured the ion current produced from a copper target. We also captured long exposure images of the target and found that the beam does produce visible light. While we have so far been unable to verify the copper spectra produced, we are modifying our apparatus with a higher-current electron gun to produce higher-intensity spectra for this experiment. [Preview Abstract] |
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D04.00026: Electron Ionization of the CN+ Molecule M S Pindzola, J P Colgan A configuration-average distorted-wave method is used to calculate electron-impact ionization cross sections for the CN+ molecule. The summed cross sections for the $3\sigma^2$, $4\sigma^2$, $1\pi^2$, and $5\sigma^2$ subshells of the ground configuration and the $3\sigma^2$, $4\sigma^2$, and $1\pi^4$ subshells of the first excited configuration are compared with summed ionization cross sections for the production of CN+2, C+, N+, C+2, and N+2 at the crossed-beams facility, Louvain-la-Neuve, Belgium. [Preview Abstract] |
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D04.00027: Electron-impact ionization of the Pb atom J P Colgan, M S Pindzola Electron-impact ionization cross sections are calculated for the ground configuration of the Pb atom. Time-dependent close-coupling cross sections for the direct ionization of the 6p subshell are combined with distorted-wave cross sections for the direct ionization of the 6s subshell and distorted-wave cross sections for the 6s -> nl excitation-autoionization contributions to compare with crossed-beams measurements made at Queen's University of Belfast, N. Ireland. [Preview Abstract] |
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D04.00028: Electron and photon ionization of the BeH molecule S D Loch, M S Pindzola One of the primary candidates as a facing component in many fusion plasma devices is Be. Erosion of the Be walls when in contribution with plasmas leads to the formation of BeH. A configuration-average distorted-wave method is used to calculate electron and photon ionization cross sections for the BeH molecule. The electron ionization cross sections are compared with previous Deutsch-Mark (DM) and Binary Encounter Bethe (BEB) calculations. The photon ionization cross sections are compared with previous Molecular-adapted Quantum Defect Orbital (MQDO) calculations. [Preview Abstract] |
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D04.00029: FROG Simulations of Femtosecond Laser Double-Pulses Affected by Different Orders of Dispersion Milan Tomin, Soroush Khosravi, Marco Scipioni, George Gibson This poster presentation reports the simulation analysis and results of FROG (Frequency-Resolved Optical Gating) traces for femtosecond laser double-pulses with different orders of dispersion. Particularly, double pulses with second, third, or fourth order dispersion were examined. The simulated double-pulses were created by splitting a transform{\-}limited pulse (center frequency$=$800nm, bandwidth $=$25 nm, and pulse duration$=$ 40 fs) into two slices in the frequency domain. While FROG traces for the case of a single laser pulse have already been simulated by different authors in an earlier work, the simulation results in this poster are novel since they represent the first FROG simulations for femtosecond laser double-pulses. This research work, which was initially conducted to characterize the output of a high energy femtosecond double-pulse stretcher, can be generalized and implemented to other instruments such as double-pulse noncolinear optical parametric amplifiers (NOPAs). Additionally, the presented simulation results and analysis could be useful in the context of applications requiring precise phase control of double{\-}pulses, such as Raman~chirped adiabatic passage (RCAP). [Preview Abstract] |
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D04.00030: The Impact of Experimentally Measured Dielectronic Recombination Rate Coefficients on Photoionized Plasmas Pierce Jackson, Michael Fogle, Stuart Loch, Francisco Guzman Electron-Ion recombination is an important process in laboratory and astrophysical plasma environments. It affects the charge states of elements, the resulting spectral emission, and many plasma diagnostic tools. This in turn impacts cosmological elemental abundance determinations. Theoretical Dielectronic Recombination (DR) rates, a type of electron-ion recombination process, are known to have large uncertainties at low electron-temperatures. These DR rates can be measured accurately using experiments, with data existing for a few ions. These experimental measurements, combined with higher energy theoretical rates, produce hybrid rates that represent the most accurate DR rate available for that ion. To determine how these hybrid rates impact plasma simulations, we use the photoionization code CLOUDY to model common low-temperature astrophysical plasma environments. Significant differences are found between simulations that use theoretical DR rates versus experimentally measured values. Given the small number of DR measurements that exist, more storage ring measurements should be conducted for astrophysically important ions. Also, theoretical advances are required for low temperature DR and photoionized plasma simulations should use the experimental DR rates in their databases. [Preview Abstract] |
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D04.00031: Sympathetic and Direct Doppler Cooling of Boron Hydride in a Radio-Frequency Ion Trap Judd Staples, Lu Qi, Evan Reed, Nikita Zemlevskiy, Jyothi Saraladevi, Kenneth Brown The radio-frequency trapping of cold molecular ions has several potential applications including precision measurement of time variation in the electron/proton mass ratio, construction of two-qubit quantum gates, and the execution of cold chemistry experiments such as controlled reactions and charge exchange observation. However, the rovibrational degrees of freedom within molecular ions make direct Doppler cooling processes experimentally difficult, necessitating additional lasers to suppress state branching. Numerical analysis predicts nearly diagonal Franck-Condon factors within vibronic transitions of BH$+$, which signifies a nearly closed cooling cycle thereby making Doppler cooling feasible [1]. By first sympathetically cooling BH$+$ within a Ca$+$ Coulomb crystal to demonstrate BH$+$ synthesis then Doppler cooling on the X$^{\mathrm{2}}\Sigma^{\mathrm{+}}\to $A$^{\mathrm{2}}\Pi^{\mathrm{+}}$ electronic transition, we aim to realize Doppler cooling of BH$+$. We report the current status of this experiment.~ [1] Nguyen, J. H. V., Viteri, C. R., Hohenstein, E. G., Sherrill, C. D., Brown, K. R., {\&} Odom, B. (2011). Challenges of laser-cooling molecular ions. New Journal of Physics, 13(6), 063023. doi: 10.1088/1367-2630/13/6/063023 [Preview Abstract] |
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D04.00032: Nanosecond Pulsed Laser Deposition of Pb Thin Film on Si (111) Bektur Abdisatarov, Devon Loomis, Ilhom Saidjafarzoda, Mikhail Khenner, Ali Oguz Er Pb thin film was deposited onto a Si (111) substrate by pulsed laser deposition (PLD). The Pb target was ablated with a Q-switched 1064 Nd: YAG pulsed laser with 5 nanosecond pulse width, 10 Hz repetition rate, and 1 mm beam diameter. Laser energy density, temperature wavelength and the number of pulses were changed. Different thicknesses of the film ranging from 5 to 70 nm were obtained. Morphological structures of the films were measured using scanning electron microscopy and atomic force microscopy. Our results show that laser energy density, wavelength, and temperature play an important role in morphology. In addition, quantum size effects (QSE) were observed on the ultra-thin films and coarsening effects were observed on the films that underwent high-temperature deposition. Experimental observation is supported by theoretical simulations. Ongoing results of Pb film growth on a copper sample will also be presented. [Preview Abstract] |
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D04.00033: Nonlinear Optical Properties of Tungsten Disulfide Atomic Layer Tikaram Neupane, Bagher Tabibi, Felix Seo The third nonlinearity of tungsten disulfide atomic layers in liquid solution was charactreized using the open and closed Z-scan techniques. The excitation was a pulsed laser with a temporal width of \textasciitilde 6 ns, a repetition rate of 10 Hz, and a spatial profile of Gaussian beam. The open Z-scan displayed the reduction of transmittance as the sample moved to focal point, which indicates the reversed saturable absorption or the positive nonlinearity of tungsten disulfide atomic layer in liquid solution. The closed Z-scan exhibited the peak-valley nonlinear transmittance as a function of sample position through the focal point, which indicated the negative nonlinearity of tungsten disulfide atomic layer in liquid solution. The normalized transmittance at the valley of closed Z-scan was decreased as the peak intensity was increased due to the negative nonlinear refraction. [Preview Abstract] |
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D04.00034: Stabilizing Apoa Protein Folding in Various Potassium Chloride Concentrations Hannah Holmberg, Luis Sanchez-Diaz Apopliprotein or Apoa1 is a complex lipoprotein that functions in the removal of cholesterol from the blood and in removing cholesterol from area around white blood cells and promoting the excretion of lipids through the lymphatic system. Previous research has found that Apoa1 shows both folded and unfolded conformations depending on the concentration of NaCl in the solution around it. The protein was studied using molecular dynamics simulations. Once this state of equilibrium was reached, various structural properties of the protein were measured including the radius of gyration and the radial distribution function. The goal of the project was to confirm the results of previous research and to set the basis for phase two of the research in which we will determine if potassium chloride allows for the same conformations of apoa to be formed. We have determined that in a range of concentrations from 0.5M to 2.0M Apoa has both folded and unfolded conformations. We are now working to study Potassium Chloride in these concentrations to determine if the radius of gyration results will be the same as the ones found in studying the sodium chloride. This research will determine if the healthier salt potassium chloride, allows for the same folded and stable conformations of apoa. [Preview Abstract] |
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D04.00035: High Functioning, Low-Cost, Myoelectric Prosthetics Payton Phelps, Preston Robinette, Eli Owens There are approximately 40 million people world-wide in need of prosthetics. However, commercial upper prosthetic devices are often prohibitively expensive, costing tens of thousands of dollars. Currently, only about 5\% of the people in the world who need a prosthetic have access to one. Highly functional, open source, low cost, 3D printed prosthetic devices will increase the number of people who have access to prosthetics. This project aims to design and develop myoelectric sensing and interpretation technology for integration with naturally controlled 3D printed prosthetics, resulting in low cost upper prosthetics. Myoelectric prosthetics use the potential difference across contracting muscles for control. For this work, we are using machine learning algorithms to classify the signals into individual digit movements. To implement these algorithms, we plan to build a suitable database of signals from various users, increasing the adaptability of the model. Producing an open source, myoelectrically controlled prosthetic that adapts to and learns about its user will present a huge improvement in 3D printed prosthetics and help many people worldwide. [Preview Abstract] |
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D04.00036: Analysis of a Self-Propelled Particle Model for Understanding Flocking Transition in Sperm Paul Yanka, Jelani Lyles, Daniel Sussman, M. Lisa Manning, Chih-Kuan Tung Self-propelled particle (SPP) model has been used to derive useful knowledge in active matter systems for more than two decades. When there is no alignment between particles, there is a known phase separation of a condensed phase and a dilute phase solely due to the volume exclusion called motility induced phase separation (MIPS). When there is alignment between particles, there is a flocking transition. The goal of our SPP model is to help us understand experimental observation, and we focus on showing that our model produces comparable results with known literature. When we used a quadratic repulsion potential with no alignment, cell density fluctuation was seen when 7,000 particles were placed in the system, similar to other observation from MIPS, while the mean squared displacement (MSD) scales linearly with time to show a purely diffusive motion. When alignment was introduced and flocking occurred, we saw the MSD to scale with time quadratically, in line with particles going in a fixed direction. Along with the correlation function measurement, we have established a framework for the analysis of the SPP model, and we look to help better understand the origin of sperm flocking in experiments. [Preview Abstract] |
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D04.00037: Studies on the Relationship Between the Local Pressure Tensor Field and the Forces Acting on Particles in Simple Molecular Models J. Matthew Mansell Over the past decade, numerous research efforts have resulted in a growing body of evidence indicating that components of the local pressure tensor field attain values of very large magnitude in many nanopore-adsorbate systems, and that many unique properties of these systems can be explained by these large-magnitude values. Here, I present results of computational measurements of the local pressure field (using the Irving-Kirkwood definition), as well as the mean compressive force acting on particles, in a series of typical nanopore-adsorbate models, as well as in bulk fluids. In agreement with the works mentioned above, I find that certain components of the local pressure field in the pore-adsorbate systems indeed attain extrema with very large magnitudes, whereas the magnitudes of the extrema in the bulk systems are much smaller. I also find that the average compressive forces acting on the particles in either type of system are very similar. Hence, although the local pressure can be very high in the nanopore-adsorbate systems, this does not suggest that the compressive forces acting on the particles in those systems is significantly larger than in bulk fluids, contrary to the naïve interpretation. [Preview Abstract] |
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D04.00038: Fabrication and characterization of devices made of graphene encapsulated in hexagonal boron nitride Andy Wang, Andrew Seredinski, Gleb Finkelstein Hexagonal boron nitride (hBN) encapsulated graphene provides a platform for the manifestation of exotic phenomena, such as the integer and fractional quantum Hall effects. The encapsulating hBN layers protect the graphene device from external charge and surface inhomogeneity. These heterostructures are fabricated by stacking layered materials through dry-transfer stamping of each layer. Throughout this process, blisters form in the interfaces between the hBN and graphene layers, reducing device quality and limiting the usable size of a device. Hence, it is essential to develop a consistent and clean device fabrication procedure that minimizes blister formation while maximizing device size and quality. We review and present optimizations on various aspects of the fabrication process, including layered material exfoliation, stamp fabrication, stacking strategies, and cleaning procedures. To evaluate these procedures, we identify blister formation with atomic force microscopy and graphene quality via Raman spectroscopy. [Preview Abstract] |
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D04.00039: Designing an atomic force microscope (AFM) for a wider range of researchers Elizabeth Reiner, Theda Daniels-Race Atomic force microscopy (AFM) is a technique used in a variety of research fields to characterize samples at resolutions approximately 1000x better than optical microscopes. A standard AFM relies on the interaction between the atoms of a needle-like cantilever and the atoms on the sample surface to repel the cantilever from the sample. The instrumentation of even a so-called "plug and play" commercial AFM still requires the user to exercise intense dexterity and control to calibrate a laser before the sample can be characterized. In this project, we have researched and designed the parameters needed for a prototype AFM which makes this equipment and technique that much more accessible to a wider range of researchers. The end goal of this work is to design and produce a homemade atomic force microscope (AFM) that is accessible to more researchers by meeting the following goals: (1) less expensive than a commercial AFM, (2) portable/modular, and (3) easier to use than a conventional AFM. Thus, in this project we have researched, selected, and designed a customized AFM probe-controller system best suited to these criteria while, in addition, successfully simulating and testing critical circuit operations. [Preview Abstract] |
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D04.00040: Post-thermal treatment characterization of optically transparent polymer and dye pH sensing films Daniela Topasna, Gregory Topasna Thin films fabricated using the ionically self-assembled monolayers (ISAM) technique incorporating poly(allylamine hydrochloride) and Direct Yellow 4 for optically transparent pH sensing films were created. These films have potential applications in the food industry, biomedical, or environmental fields, especially for remote sensing. The absorption of the film changes when the pH of the surrounding medium changes. Films were characterized by atomic force microscopy and absorbance measurements before and after thermal treatment. The pH sensing properties remain unchanged upon exposure to a range of temperatures. [Preview Abstract] |
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D04.00041: Investigating magnetization dynamics in Y-shaped nanostructures via micromagnetic simulations. Pasquale Ferraro, Aron Guerrero, H. J. Jason Liu Recently, scalable magnetic devices have shown potential to be useful in future electronics. One such device is known as a magnonic device, which uses spin waves or magnons to transfer spin information. On their own, spin waves are only detectable for a short distance, typically a few micrometers in metallic materials due to intrinsic damping. In this work, we are using micromagnetic simulations to study the interference of spin waves and their effects on propagation length. Micromagnetic simulations allows for the analysis of spin dynamics in magnetic materials with specific structural geometries. One type of structure that we are investigating is a Y-shaped nanostructure. Current relaxation studies with this structure show that the magnetization is aligned with the geometric boundaries. I will discuss our current progress towards generating spin waves in the Y-shaped nanostructure in both the forward volume configuration and the backward volume configuration, as well as, experimental development of these structures. [Preview Abstract] |
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D04.00042: Influence of Oxygen Pressure during the Deposition on the Properties of Amorphous Fe:Dy Oxide Films Olivia Denton, Sara Bey, Tatiana Allen, William Roes, Krishna Koirala, Ramki Kalyanaraman A new material composed of~FeDy oxide~has~shown an interesting combination of properties such as high electrical conductivity, Hall mobility, and optical transparency and room temperature ferromagnetism which presents a promise for applications across many fields of electronics. Here we report results of initial characterization of a large group of FeDyO thin films prepared by the e-beam evaporation. The technological parameters varied during the deposition were relative amounts of Fe and Dy in the films, and the oxygen partial pressure in the chamber. Films were deposited on two kinds of substrates: SiO$_{\mathrm{2}}$/Si and Quartz. Fe to Dy ratio in the films was measured by the EDS. Data on optical transmission, electrical conductivity Hall effect, and magnetoresistivity of as-deposited films were collected at room temperature to see how the deposition parameters, especially the oxygen partial pressure, influence the properties of as-deposited films. [Preview Abstract] |
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D04.00043: A review of electrophoretic deposition of molybdenum disulfide (MoS$_{\mathrm{2}})$ Christopher Connell, Theda Daniels-Race Electrophoretic Deposition (EPD) is a cost effective room temperature technique applicable to a wide range of deposition materials used in the formation of near atomically flat films on several substrate types. This review will present some of the basics of EPD along with a selection of recent methods being investigated to realize this technique as a technologically feasible and commercially competitive method for large scale reproducible deposition. The current trend among a significant segment of EPD researchers is to focus on the deposition of carbon nanotubes. However, there has been a notable interest in the use of EPD for other materials such as transition metal dichalcogenides (TMDCs). For this poster we will focus on the deposition of the TMDC molybdenum disulfide (MoS$_{\mathrm{2}})$ due to its ability to form thin films with a tunable bandgap dependent on the thickness of the film. [Preview Abstract] |
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D04.00044: Correlation between Growth Dynamics and Optical Properties of Gadolinium Doped Indium Tin Oxide Tin Films Daniel Hirt, Will Riffe, Scott Bender, David Lawrence, Costel Constantin Indium Tin Oxide (ITO) semiconductor family is widely used across the electronic industry as touch-screen material because of its high electrical conductivity and high transparency. The goal of our project is to investigate the correlation between growth dynamics and optical properties of Indium Tin Oxide (ITO) and Gadolinium doped ITO (Gd-ITO) thin films which were deposited with Direct-Current Magnetron Sputtering. These films were deposited at room-temperature and they were opaque as removed from the growth chamber, however, after annealing them in air and inert atmosphere, the films became transparent. To measure optical properties such as index of refraction (n), extinction coefficient (k), and band gap (Eg) we used variable angle spectroscopic ellipsometry (VASE) and UV-Vis transmission spectroscopy. We model our data by using both VASE and UV-Vis and compare it with data only modeled by using VASE. [Preview Abstract] |
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D04.00045: Radioactive Decay Simulations for Testing of the Timing Detectors in the Nab Experiment Rebecca Godri, Joshua Hamblen, Aaron Jezghani, Derek Holman Located at the Spallation Neutron Source in Oak Ridge National Lab, the Nab experiment aims to yield a measurement of the electron-neutrino correlation parameter, a, and the Fierz interference term, b, in neutron beta decay. These parameters are located in the energy and the angular distribution of the particles produced through neutron beta decay. Using silicon detectors, a direct measurement of the phase space distribution of the resultant electron energy and proton momentum can be obtained. The silicon detectors of the Nab experiment will be tested using well-known radioactive isotopes. Simulations of systematic testing use the associated energy levels, decay probabilities, and decay options of radioactive sources such as ${}^{139}$Ce, ${}^{133}$Ba, and ${}^{113}$Sn to determine the expected results of experimental testing. Presented here is an analysis of the Monte Carlo simulations of the radioactive decay of ${}^{139}$Ce, ${}^{133}$Ba, and ${}^{113}$Sn and their ability to be useful to the Nab experiment as a whole. [Preview Abstract] |
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D04.00046: The Cosmic Radiation Shielding Properties of Lunar Regolith Eleanor Murray Lunar regolith is the most accessible material for use as radiation shielding for human habitation on the Moon. This study aims to determine the thickness of lunar regolith shielding necessary to protect humans from cosmic radiation and its secondaries, including neutrons. We measured the percentage of thermal neutrons that passed through LHS-1 Lunar Highlands Simulant samples of different thicknesses at the Neutron Powder Diffraction Facility at the PULSTAR Reactor at NC State University, prepared for a neutron transmission experiment. We also model our neutron transmission experiment using Geant4. We present the results of this experiment as well as preliminary results of the necessary thickness at which the radiation dose will drop to safe levels based on Geant4 simulations of the interactions of galactic cosmic rays with the lunar regolith-like~ material. [Preview Abstract] |
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D04.00047: Measurements of Photonuclear Reaction Pathways towards Promising Medical Radioisotopes Funmilola Noiki We report on measurements of photo-nuclear cross-sections which lead to the production of isotopes which are of interest in medical diagnosis and treatment sciences. Precise measurements of the cross sections of $^{\mathrm{48}}$Ti ($\gamma $, p), $^{\mathrm{48}}$Ti ($\gamma $, n), $^{\mathrm{48}}$Ti ($\gamma $, pn), $^{\mathrm{48}}$Ti ($\gamma $, 2n), $^{\mathrm{48}}$Ti ($\gamma $, \textunderscore ), $^{\mathrm{197}}$Au ($\gamma $, n) and $^{\mathrm{197}}$Au ($\gamma $, pn) were made at gamma ray energies between 22 -27 MeV. The High Intensity Gamma Ray Source (HI$\gamma $S) of Triangle Universities Nuclear Laboratory (TUNL), a Compton $\gamma $-ray facility employing a high intensity Free-Electron Laser (FEL) produced the gamma ray beams for the study. The activity of the reaction products was measured at TUNL's low-background counting facility using High Purity Germanium detectors (HPGe). Lifetime data were fitted to obtain the isotope yields. Cross-section data are compared to calculations and other known available measurements, such as photo-nuclear cross sections of gold (Au) isotopes. This study reports on the techniques, methods, and results obtained from this measurement. [Preview Abstract] |
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D04.00048: Neutrinoless Double Beta Decay through Argon 40 Data Ryan Goodwin, Scott Woolard Two-proton drop-off reactions can test the Bardeen-Cooper-Schrieffer (BCS) approximation used to describe the ground states in Quasi-Random Phase Approximation (QRPA) calculations of double beta-decay nuclear matrix elements (NME). $^{\mathrm{134,136}}$Xe($^{\mathrm{3}}$He,n) reaction measurements have been carried out at the TUNL tandem laboratory to test the BCS approximation for $^{\mathrm{136}}$Xe double-beta decay. The measurements were carried out using a neutron time of flight system with a 13 m flight path, achieving a 3 ns timing resolution. We will report on analysis of $^{\mathrm{40}}$Ar($^{\mathrm{3}}$He,n) cross-sections carried out with the same experimental setup to characterize systematic errors. [Preview Abstract] |
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D04.00049: A review of how Thickness of a broad Plate and choice of Material (or Isotope) of this Plate effect the Attenuation, Transmission, and `diffuse' Reflection of a Beam of Neutrons which enters this Plate Lars Hebenstiel, Eric Steinfelds This computational investigation currently limits itself to nonfissionalble materials for the Target plate. We consider the scattering of neutrons on solid rectangular targets. It is standard to treat this problem using the Maxwell Boltzmann Transport Equation (MBTE) and to use symmetries to simplify the calculation. The solving of the MBTE has proven itself to be very difficult so solve analytically and even challenging with deterministic numerical approaches. Monte Carlos simulations of scattering of neutrons offer patterns of numerical solutions which can be statistically surmised for rectangular slabs and other target barriers. We offer a method in which first order isotropic scattering is calculated analytically. 2$^{\mathrm{nd}}$ order through 10$^{\mathrm{th}}$ order scattering are done semi-analytically with a skillful use of logs and polynomials to fit Exponential Integral (EI) functions. Although the MBTE by nature is a 5 variable equation, spherical phase symmetry of the n's makes it possible to simplify the MBTE into Fredholm integral equation of 2$^{\mathrm{nd}}$ kind. These deterministic calculations are compared to Monte Carlo simulations of scattered neutrons from corresponding targets of material. [Preview Abstract] |
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D04.00050: Self-energies in a relativistic chiral effective theory Marston Copeland, Chueng-Ryong Ji, Wally Melnitchouk We calculate the self-energies of the flavor SU(3) octet and decuplet baryons, using a relativistic chiral effective theory framework consistent with Lorentz and gauge invariance. The results are compared using several different regularization prescriptions, including the finite-range regularization, Pauli-Villars, and dimensional regularization, which are shown to yield the same leading nonanalytic behaviors in the chiral limit, as expected in QCD. There is an emphasis on the full relativistic finite-range regularization, and new details of this calculation are explored for self-energies. [Preview Abstract] |
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D04.00051: Dynamic Jet Charge Tyler Wilson, Sonny Mantry, Mark Spraker, Zhongbo Kang, Xiaohui Liu The ``Jet Charge" is a potentially useful tool for identifying the hard-process partons that initiate jets produced in high energy collisions. The standard jet charge definition corresponds to a momentum-weighted sum of electric charges of the particles clustered within a jet. In this work, we explore modifications of the standard Jet Charge definition with the aim of improving the discrimination between quark- and gluon-initiated jets. Such modifications could be particularly useful in heavy ion collisions, where the noisy environment reduces the effectiveness of standard techniques of quark and gluon jet discrimination. Preliminary results on the effectiveness of the modified jet charge definitions in discriminating between quark and gluon jets, based on Monte Carlo simulations, will be presented. [Preview Abstract] |
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D04.00052: Using Bayesian Neural Networks to Make Predictions from Supersymmetry Theories Braden Kronheim, Alexander Karbo, Michelle Kuchera, Raghuram Ramanujan One of the goals in current particle physics research is to obtain evidence for theories beyond the Standard Model (BSM). Many of these theories are high dimensional, which makes searching through their possible predictions difficult. For this project, machine learning was used to make predictions from a simplified supersymmetric model, namely the phenomenological Minimal Supersymmetric Standard Model (pMSSM), a BSM theory with 19 free parameters. Specifically, a Tensorflow implementation of Bayesian Neural Networks was developed for this project to leverage modern day Graphics Processing Units in both the training and prediction phase and obtain confidence intervals. This algorithm was then used to learn to predict cross sections for arbitrary pMSSM parameter combinations, the mass of the Higgs boson they create, and the theoretical validity of the points. All three targets were predicted to a high degree of accuracy with 4.27 percent error or less and can now be used to make predictions significantly faster than traditional methods, with the cross section prediction occurring over 10 million times faster than previous algorithms. These results demonstrate the potential for machine learning to help probe these high dimensional spaces in BSM theories. [Preview Abstract] |
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D04.00053: nEXO Cryogenics Research {\&} Development: LN2 Thermosyphon William Jarratt, Tim Daniels The nEXO Collaboration has proposed a tonne-scale search for neutrinoless double-beta (0$\nu \beta \beta )$ decay in 136Xe. While it will in many ways be modeled after its predecessor EXO-200, the increase in scale will drive some design changes, including the use of a thermosyphon system instead of refrigerators for maintaining the cryostat temperature. Cooled passively by LN2, these gravity-assisted heat transport devices utilize the phase transition of nitrogen as an internal working fluid. We are developing a thermosyphon for nEXO R{\&}D modeled on one developed for the LUX dark matter experiment. The system design, instrumentation, and control scheme will be reviewed and initial thermal testing results presented.Replace this text with your abstract body. [Preview Abstract] |
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D04.00054: NaI detector characterization for coherent elastic neutrino-nucleus scattering (CEvNS) E. Ujah, J. Sibley, D.M. Markoff, S. Hedges, C. Awe, P.S. Barbeau One goal of the COHERENT collaboration is to measure the coherent elastic neutrino-nucleus scattering (CEvNS) process in multiple targets to test agreement with the standard model predictions. Measuring the CEvNS interaction is challenging because the detection mechanism requires observing low nuclear recoil energy deposited in the crystal on the order of 10 keVee in NaI. In order to increase detection statistics, the COHERENT collaboration plans to build\^{A} a multi-ton Sodium Iodide detector constructed of multiple 7.7 kg NaI[Tl] crystal modules. We adopted a crystal characterization procedure using known gamma-ray sources and background lines for testing the crystal quality, analyzing gain response, determining peak resolution, and evaluating the response as a function of distance along the crystal. Once the characterization of the crystals are complete, they will be deployed at the Oak Ridge National Laboratory as part of the COHERENT collaboration program. [Preview Abstract] |
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