Doctoral Dissertations

Keywords and Phrases

Pulsed Plasma

Abstract

"The objective of this research is to study the formation processes of a pulsed inductive plasma using heavy gases, specifically the coupling of stored capacitive energy into plasma via formation in a theta pinch coil. To aid in this research, the Missouri Plasmoid Experiment Mk. I (and later Mk. II) was created.

In the first paper, the construction of differential magnetic field probes are discussed. The effects of calibration setup on B-dot probes is studied using a Helmholtz coil driven by a vector network analyzer and a pulsed-power system. Calibration in a pulsed-power environment yielded calibration factors at least 9.7% less than the vector network analyzer.

In the second paper, energy deposition into various gases using a pulsed inductive test article is investigated. Experimental data are combined with a series RLC model to quantify the energy loss associated with plasma formation in Argon, Hydrogen, and Xenon at pressures from 10-100 mTorr. Plasma resistance is found to vary from 25.8-51.6 mΩ; and plasma inductance varies from 41.3-47.0 nH. The greatest amount of initial capacitively stored energy that could be transferred to the plasma was 6.4 J (8.1%) of the initial 79.2 ± 0.1 J.

In the third paper, the effects of a DC preionization source on plasma formation energy is studied. The preionization source radial location is found to have negligible impact on plasma formation repeatability while voltage is found to be critical at low pressures. Without preionization, plasma formation was not possible. At 20 mTorr, 0.20 W of power was sufficient to stabilize plasma formation about the first zero-crossing of the discharge current. Increasing power to 1.49 W increased inductively coupled energy by 39%. At 200 mTorr, 4.3 mW was sufficient to produce repeatable plasma properties"--Abstract, page iv.

Advisor(s)

Rovey, Joshua L.

Committee Member(s)

Castano Giraldo, Carlos Henry
Grabowski, Chris
Pommerenke, David
Riggins, David W.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Aerospace Engineering

Sponsor(s)

United States. Air Force. Office of Scientific Research

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2014

Journal article titles appearing in thesis/dissertation

  • Comparison of magnetic probe calibration at nano and millitesla magnitudes
  • Energy analysis of a pulsed inductive plasma through circuit simulation
  • Effects of DC preionization voltage and radial location on pulsed inductive plasma formation

Pagination

xii, 96 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2014 Ryan Alan Pahl, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Plasma accelerators
Argon
Xenon

Thesis Number

T 10619

Electronic OCLC #

902735514

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