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Full-Text Articles in Physical Sciences and Mathematics

Extending Core-Collapse Supernova Simulations: From The Onset Of Explosion To Shock Breakout, Michael A. Sandoval Aug 2021

Extending Core-Collapse Supernova Simulations: From The Onset Of Explosion To Shock Breakout, Michael A. Sandoval

Doctoral Dissertations

A core-collapse supernova (CCSN) is the result of a massive star’s core collapsing due to the inability of electron degeneracy pressure to provide sufficient support against gravity. Currently, there is a disconnect between when most three-dimensional CCSN simulations end (seconds) and when the explosion would reach the surface of the star and become visible (hours to days). We present three-dimensional simulations of CCSNe using the FLASH code that follow the progression of the explosion to the stellar surface, starting from neutrino-radiation hydrodynamic simulations of the first seconds performed with the Chimera code. We consider a 9.6-M zero-metallicity progenitor, starting …


Study Of 134in Beta-Delayed Neutron Emission And Development Of A New Generation Neutron Detector, Joseph Heideman May 2021

Study Of 134in Beta-Delayed Neutron Emission And Development Of A New Generation Neutron Detector, Joseph Heideman

Doctoral Dissertations

Beta-delayed neutron emission in very neutron-rich nuclei plays an essential role in nuclear structure and the understanding of the astrophysical r-process. A complete description of this process requires knowledge of both steps, beta decay and neutron emission. A leading theory poses the intermediate daughter nucleus to behave as a compound nucleus. The conditions for beta-delayed neutron emission of 134In are not well described by the assumptions in the neutron pandemonium hypothesis, therein providing a unique case to this process due to the proximity to 132Sn. Single-particle states in 133Sn obvserved after neutron emission have dissimilar shell occupancy compared to neutron-hole …


Expanding Band Parameter Analysis Methods For Hed Meteorites And V-Type Asteroids, Noah Adm Haverkamp Frere May 2021

Expanding Band Parameter Analysis Methods For Hed Meteorites And V-Type Asteroids, Noah Adm Haverkamp Frere

Masters Theses

Vesta and Vesta-like asteroids have been convincingly linked, through visible and near-infrared (VNIR; 0.7 - 2.5 µm [micron]) spectral analysis, to a clan of basaltic achondritic meteorites – howardites, eucrites, and diogenites (HEDs). VNIR reflectance spectra of V-type asteroids and HED meteorites have two absorption features centered near 1 µm (Band I) and 2 µm (Band II) caused primarily by Fe2+ [iron] and Ca2+ [calcium] cations in pyroxene. Previous studies have shown a correlation between the mol% Fs and Wo with the central wavelengths of Band I and Band II, hereafter called Band I Center (BIC) and Band …