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Title: Plasma instability in fast spherical discharge induced by a preionization

As it was shown earlier, fast discharge (dI/dt ∼ 10{sup 12 }A/s and I{sub max} ≈ 40 kA) in a spherical cavity (Al{sub 2}O{sub 3}, inner diameter 11 mm, 4 mm apertures for the current supply) filled with working gas (Ar and Xe, pressure 80 Pa), results in the formation of a plasma with the form close to spherical. The physical mechanism can be the cumulation of a convergent shock wave, which was originated near the inner surface of the discharge cavity. It was also shown for the cylindrical fast discharge that the preionization influences the dynamics of the cylindrical convergent shock wave, its evolutions becomes faster. The present work is devoted to the study of the influence of the preionization on the plasma formation in the fast discharge with spherical geometry (Ar, 80 Pa). The inductive storage with plasma erosion opening switch was used as a current driver. The spatial structure of the discharge plasma was studied by means of a pin-hole camera with the microchannel plate (MCP) detector with time gate of 5 ns. The extreme ultra violet spectra were studied by means of the grazing incidence spectrometer with the same MCP detector with time gate of 20 ns. Beside the expected effects (reduction of the spherical plasma formation timemore » and some increase of the electron temperature), the preionization of the discharge by the current 500 A results also in the development of the plasma instabilities and destruction of the compact plasma ball in several tens of nanoseconds. Possible mechanism of the instability is discussed.« less
Authors:
;  [1]
  1. Department of Atomic Spectroscopy, Institute for Spectroscopy Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 142190 (Russian Federation)
Publication Date:
OSTI Identifier:
22399377
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM OXIDES; CYLINDRICAL CONFIGURATION; ELECTRIC CURRENTS; ELECTRIC DISCHARGES; ELECTRON TEMPERATURE; MICROCHANNEL ELECTRON MULTIPLIERS; PLASMA; PLASMA INSTABILITY; PLASMA PRESSURE; PLASMA PRODUCTION; PLASMA SWITCHES; SHOCK WAVES; SPHERICAL CONFIGURATION