High Yield Argon Z-pinch Results with a Large Diameter Nozzle

Journal Article · Thu Jan 05 04:00:00 EST 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2159346· OSTI ID:20729242

Levine, J S; Banister, J; Failor, B H; Qi, N; Steen, P; Sze, H; Wilson, A ^[1]; Velikovich, A L; Davis, J ^[2]; Lojewski, D ^[3]

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1. Titan Corporation/Pulse Sciences Division, San Leandro, California 94577 (United States)
2. Plasma Physics Division, Naval Research Laboratory, Washington D.C. 20375 (United States)
3. Defense Threat Reduction Agency, Albuquerque, New Mexico 87117 (United States)

We modified our original 12 cm diameter double-shell gas puff nozzle to include an on-axis jet with a large diameter throat and an independent plenum to allow a large fraction of the total mass to be contained in the central region (r=0-1.5 cm). By judicious selection of pressures for the jet and the two shells, we were able to double the Argon K-shell yield from {approx}10 kJ to > 20 kJ with a 3.5 MA current drive and implosion time of {approx}205 ns, equivalent to the yield produced at 100 ns implosion time, but with half the pulse-width, for radiated K-shell power up to 2 TW.The radiation produced by gas originating in each of the three plenums was distinguished by the use of a chlorine tracer introduced sequentially into each plenum. We thereby deduce that 65% of the K-shell radiation is produced by gas originating in the jet, 30% from gas originating in the inner shell and only 5% from gas originating in the outer shell.The flexibility of the hardware was further exercised by selectively evacuating one of the three plenums. We were thus able to demonstrate the crucial role of the inner shell in stabilizing the implosion of the outer shell gas before impinging on the central jet. Furthermore, by leaving off the outer shell gas to simulate a 6 cm diameter single-shell on jet nozzle, we demonstrated high yield at long implosion time without as large a nozzle as previously required.This research points the way to improved nozzles for long pulse drivers that eliminate the long implosion time (Y{approx}1/{tau}) penalty and opens the possibility of practical higher atomic number gas puff experiments on existing drivers.

• OSTI ID: 20729242
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 808; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ARGON
CHLORINE
FLEXIBILITY
IMPLOSIONS
K SHELL
LONGITUDINAL PINCH
NOZZLES
PLASMA JETS
PULSES