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Full-Text Articles in Physical Sciences and Mathematics

Calibration Of The Lux-Zeplin Dual-Phase Xenon Time Projection Chamber With Internally Injected Radioisotopes, Christopher D. Nedlik Jun 2022

Calibration Of The Lux-Zeplin Dual-Phase Xenon Time Projection Chamber With Internally Injected Radioisotopes, Christopher D. Nedlik

Doctoral Dissertations

Self-shielding in ton-scale liquid xenon (LXe) detectors presents a unique challenge for calibrating detector response to interactions in the detector's innermost volume. Calibration radioisotopes must be injected directly into the LXe to reach the central volume, where they must either decay away with a short half life or be purified out. We present an overview of, and results from, the prototype source injection system (SIS) developed at the University of Massachusetts Amherst for the LUX-ZEPLIN experiment (LZ). The SIS is designed to refine techniques for the injection and removal of precise activities of various calibration radioisotopes that are useful in …


Tokamak 3d Heat Load Investigations Using An Integrated Simulation Framework, Thomas Looby May 2022

Tokamak 3d Heat Load Investigations Using An Integrated Simulation Framework, Thomas Looby

Doctoral Dissertations

Reactor class nuclear fusion tokamaks will be inherently complex. Thousands of interconnected systems that span orders of magnitude in physical scale must operate cohesively for the machine to function. Because these reactor class tokamaks are all in an early design stage, it is difficult to quantify exactly how each subsystem will act within the context of the greater systems. Therefore, to predict the engineering parameters necessary to design the machine, simulation frameworks that can model individual systems as well as the interfaced systems are necessary. This dissertation outlines a novel framework developed to couple otherwise disparate computational domains together into …


Synthesis, Fabrication, And Assembly Of Mesoscale Polymer Filaments, Dylan M. Barber Mar 2022

Synthesis, Fabrication, And Assembly Of Mesoscale Polymer Filaments, Dylan M. Barber

Doctoral Dissertations

Mesoscale materials, with feature sizes in the range of one hundred nanometers to tens of micrometers, are ubiquitous in Nature. In organisms, mesoscale building blocks connect the properties of underlying molecular and nanoscructures to those of macroscale, organism-scale materials through hierarchical assemblies of recurring structural motifs. The collective action of large numbers of mesoscale features can afford stunning features like the structural color of the morpho butterfly wing, calcium ion-mediated movement in muscle, and wood structures like xylem that can support enormous external compressive loads and negative internal pressure to transport nutrients throughout an organism. In synthetic systems, the design, …