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Title: Study of gas-puff Z-pinches on COBRA

Gas-puff Z-pinch experiments were conducted on the 1 MA, 200‚ÄČns pulse duration Cornell Beam Research Accelerator (COBRA) pulsed power generator in order to achieve an understanding of the dynamics and instability development in the imploding and stagnating plasma. The triple-nozzle gas-puff valve, pre-ionizer, and load hardware are described. Specific diagnostics for the gas-puff experiments, including a Planar Laser Induced Fluorescence system for measuring the radial neutral density profiles along with a Laser Shearing Interferometer and Laser Wavefront Analyzer for electron density measurements, are also described. The results of a series of experiments using two annular argon (Ar) and/or neon (Ne) gas shells (puff-on-puff) with or without an on- (or near-) axis wire are presented. For all of these experiments, plenum pressures were adjusted to hold the radial mass density profile as similar as possible. Initial implosion stability studies were performed using various combinations of the heavier (Ar) and lighter (Ne) gasses. Implosions with Ne in the outer shell and Ar in the inner were more stable than the opposite arrangement. Current waveforms can be adjusted on COBRA and it was found that the particular shape of the 200‚ÄČns current pulse affected on the duration and diameter of the stagnated pinchedmore » column and the x-ray yield.« less
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1] ; ; ;  [2]
  1. Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)
  2. Weizmann Institute of Science, Rehovot 76100 (Israel)
Publication Date:
OSTI Identifier:
22403274
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ARGON; ELECTRON DENSITY; FLUORESCENCE; INSTABILITY; LASERS; NEON; PULSES