Plasma dynamics studies on the Los Alamos Solid Fiber Z-Pinch

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:243734

Riley, R A; Scudder, D W; Shlachter, J S ^[1]

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1. Los Alamos National Lab., NM (United States); and others

The Los Alamos High Density Z Pinch-II (HDZP-II) experiments is being used to study the dynamics of z-pinch plasmas generated from thin solid fibers of deuterated polyethylene (CD{sub 2}). A model has been developed which incorporates anomalous heating due to instability-generated turbulence. HDZP-II uses a pulsed-power generator that delivers a current of up to 1 MA with a 100 ns rise-time through an inductive load. The surface of the solid fiber, with a 5-cm length and 3-50{mu}m radius, immediately ionizes and rapidly expands in radius. As the plasma is heated, more and more of the fiber is ablated until the entire fiber is ionized. The fully ionized fiber continues to expand radially. Diagnostics include a multi-frame shadowgraph, a three channel X-ray crystal reflection monochromometer, a single frame point-diffraction interferometer, neutron detectors, and generator monitors. The shadowgraph provides the plasma shape in seven frames taken at 10-ns intervals. This has shown very strong m=0 instability at the onset of current, even for small pre-pulse currents. The interferometer provides the plasma line density and, assuming cylindrical symmetry, the electron density. This is used to {open_quotes}calibrate{close_quotes} how much of the plasma is contained in the shape given by the shadowgraphs. The author have chosen a small enough aperture to have most of the plasma in the shadowgraph. The X-ray monochromometer provides the electron temperature as a function of time. The temperature generally rises to 90 eV at 40 ns into the current and remains very flat until near the end of the current ramp. The results from these diagnostics and their bearing on anomalous turbulent heating will be presented.

• OSTI ID: 243734
• Report Number(s): CONF-9304297--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 2 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DEUTERIUM COMPOUNDS
DYNAMICS
LINEAR Z PINCH DEVICES
PLASMA
PLASMA DIAGNOSTICS
POLYETHYLENES
TURBULENCE