Physical Sciences and Mathematics Commons^™

Size Limits And Fission Channels Of Doubly Charged Noble Gas Clusters, Ianessa Stromberg, Stefan Bergmeister, Lisa Ganner, Fabio Zappa, Paul Scheier, Olof Echt, Elisabeth Gruber

Faculty Publications

Small, highly charged liquid droplets are unstable with respect to spontaneous charge separation when their size drops below the Rayleigh limit or, in other words, their fissility parameter X exceeds the value 1. The absence of small doubly charged atomic cluster ions in mass spectra below an element-specific appearance size n_a has sometimes been attributed to the onset of barrierless fission at X = 1. However, more realistic models suggest that n_a marks the size below which the rate of fission surpasses that of competing dissociative channels, and the Rayleigh limit of doubly charged van der Waals clusters …

Energy Analysis For Neutron Induced Ternary Fission Events In The Niffte Fission Time Projection Chamber, Vanessa Aguilar

Physics

In this paper, energy analyses were made for investigating ternary fission in neutron-induced fission of U235 and U238 using the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration’s fission time projection chamber (TPC) data. The Neutron kinetic energy was calculated from neutron time of flight (nToF) for energy ranges of 0.1 to 32 MeV. Along with this, the Stopping and Range of Ions in Matter (SRIM) software was used to simulate alphas going through an argon gas target in order to calibrate observed energy loss of alphas from ternary fission.

Finding And Analyzing U235 And U238 Ternary Fission Events In The Niffte Fissiontpc, Gabriel A. Oman

Physics

In this analysis, the differences between ternary and binary fission were explored using data from the NIFFTE Collaboration’s fission time projection chamber (TPC). The ratio of binary-to-ternary events for U-235 and U-238 as a function of neutron kinetic energy in the range of 1-30 MeV is presented. The typical value of the ratio is approximately 105 binary fissions per ternary fission, in agreement with previously published measurements. Future work will involve distinguishing the fissions of the two isotopes to provide more insight into this rare process.

Investigation Of Neutron Induced Ternary Fission With The Niffte Time Projection Chamber, Alex C. Kemnitz

Physics

Ternary fission is a rare occurrence in which three particles are produced from a single fission event. This analysis uses tracked fission event data recorded by NIFFTE’s time projection chamber with a series of refined cuts to isolate all possible ternary events. The experiment used two targets, each consisting of two isotopes; one target was Pu-239 and U-235, and the other was U-238 and U-235. The data was used to measure the ternary/binary fission ratios for each isotope. The ratios for the Pu-239 and U-235 target that were found are shown to be too high due to alpha contamination. The …

Fission Fragment Tracking And Identification In The Neutron-Induced Fission Fragment Tracking Experiment’S Time Projection Chamber, Eric Song

Physics

The Neutron-Induced Fission Fragment Tracking Experiment (NIFFTE) built a novel Time Projection Chamber (TPC), the FissionTPC, for measuring neutron-induced fission cross-sections to unprecedented precision. We investigated data from a 2014 run (400010151) at the Los Alamos Neutron Science Center (LANSCE) with a double-sided U235/Pu239 target. Our particle identification studies will aid in the development of improved tracking algorithms.

Microscopic Description Of Nuclear Fission At Finite Temperature, Jordan David Mcdonnell

Doctoral Dissertations

While a predictive, microscopic theory of nuclear fission has been elusive, advances in computational techniques and in our understanding of nuclear structure are allowing us to make significant progress. Through nuclear energy density functional theory, we study the fission of thorium and uranium isotopes in detail. These nuclides have been thought to possess hyperdeformed isomers in the third minima of their potential energy surfaces, but microscopic theories tend to estimate either shallow or non- existent third minima in these nuclei. We seek an explanation in terms of neutron shell effects. We study how the fission pathways, the symmetry, and the …

The Economics Of The Atomic Bomb: Cost And Utilization, Jonathan M. Davis Mr.

Senior Honors Theses

Few moments in human history can be compared to the culmination of events that brought the atomic bomb into creation. It is incredible to contemplate that while a nation was fighting a two front war that spanned from Europe into the Pacific, that the United States was able to utilize the time, energy, brains, materials, manpower, and capital to complete a project in four years. That under any other circumstances would have taken greater than half a century to complete.

First, this thesis will discuss breakthroughs in research that led scientists to believe that the atomic weapons could be built, …