POS density measurements on GIT-8

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:163113

Weber, B V; Commisso, R J ^[1]; Kim, A A ^[2]

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1. Naval Research Lab., Washington, DC (United States)
2. High Current Electronics Inst., Tomsk (Russian Federation); and others

A collaborative experiment was carried out on the GIT-8 generator at the High Current Electronics Institute, Tomsk, Russia, to measure the plasma density in a 3 MA, 1 {micro}s conduction time plasma opening switch (POS). A He-Ne laser interferometer, similar to one used on the Hawk POS experiment at NRL, was adapted to GIT-8. The line-integrated electron density was measured using an axial line-of-sight through the plasma injection region. A total of 26 GIT-8 shots were taken, first: to measure the line-integrated density at different radial locations between the inner (cathode) and outer (anode) conductors, and second: to vary the conduction time at one interferometer location. The radial density measurements show an increase in the plasma inventory during conduction, evidence of ionization. At radial locations near the cathode, the density decreases prior to opening. The density near the anode increases monotonically during conduction and opening. The authors conclude that the POS probably opens a small gap in the vicinity of the cathode, but they were not able to find a line-of-sight where the density decreased to zero, either because the gap is smaller than the laser beam (3 mm), the gap is curved or slanted, or because plasma moves axially into the tube used to separate the exit window from the coaxial POS section.

• OSTI ID: 163113
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
OPERATION
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA GUNS
PLASMA SWITCHES
PULSE GENERATORS