Publication:
Laser plasma particle velocities

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Authors
Callahan, Daniel James
Subjects
Laser
Laser damage
Laser operation
Plasma
Plasma velocities
Advisors
Schwirzke, Fred R.
Date of Issue
1976-06
Date
June 1976
Publisher
Language
en_US
Abstract
Experiments were performed on laser produced plasma from aluminum target discs in a vacuum chamber at pressures a few times 10(-6) torr. Plasma analysis was achieved using a floating double electrostatic probe of tungsten wires biased at -15 volts DC. In analyzing 376 oscilloscope trace pictures of the probe signal, four velocity signals occurred with regularity. The plasma velocities detected by the probe were determined to be 3.7 X 10(7) cm/sec, 1.5 X 10(7)CM/Sec, 5.6 X 10(6) cm/sec (the bulk of the plasma) and 4.o X 10(6) cm/sec. A fifth, very fast signal at 1,0 X 10(6)cm/sec was also detected but it was not consistently present. Investigation of the velocity distributions as a function of time showed them not to be Boltzmann distributions, but exponential power distributions. Investigation of the crater formed by each laser pulse resulted in the determination of the following crater dimensions: crater depth 0.01 cm/shot, crater diameter of 0.11cm and a total spot size diameter of 0.70 cm for the laser-target interaction.
Type
Thesis
Description
Series/Report No
Department
Department of Physics and Chemistry
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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