Modeling Studies of Photoionization Experiments Driven by Z-pinch X-rays
Date
2005
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Producer
Director
Performer
Choreographer
Costume Designer
Music
Videographer
Lighting Designer
Set Designer
Crew Member
Funder
Rehearsal Director
Concert Coordinator
Advisor
Moderator
Panelist
Alternative Title
Department
Swarthmore College. Dept. of Physics & Astronomy
Type
Thesis (B.A.)
Original Format
Running Time
File Format
Place of Publication
Date Span
Copyright Date
Award
Language
en_US
Note
Table of Contents
Terms of Use
Full copyright to this work is retained by the student author. It may only be used for non-commercial, research, and educational purposes. All other uses are restricted.
Rights Holder
Access Restrictions
Terms of Use
Tripod URL
Identifier
Abstract
We have conducted modeling studies of several gas cell shots on the Z accelerator
at Sandia National Laboratories in order to study the effects of the
irradiance of a low-density gas by a strong x-ray source. Thus far, we have successfully
matched a synthesized neon absorption spectrum to an experimental
spectrum obtained from one of the shots, with especially good agreement for
many of the He-like neon absorption lines. We have also conducted a study scaling
the density of the Ne in the gas cell, and have concluded that the minimum
density for which there are still measurable spectral features is on the order of
r-v 7.5 X 1016 cm-3 , which implies an ionization parameter of r-v 70 erg cm S-l.
Lastly, we have synthesized new spectral diagnostics for future experiments in the
form of time-resolved absorption and emission spectra, and predict that future
experiments using such diagnostics will show the weakening of Li-like lines in
both absorption and emission and the strengthening of the Lyman alpha line in
emission as time progresses. These results have demonstrated we can successfully
model the photoionization experiments being conducted at Sandia, and that our
modeling procedure can be implemented to design new experiments for future
shots at Sandia. Our analysis of the excitation/ionization kinematics and physical
conditions of the photoionized plasma has also helped benchmark the atomic
kinetics models for these plasmas, which should lead to better interpretation of
measured spectra from plasmas photoionized by cosmic sources.