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Title: Generation of runaway electrons and X-ray emission during breakdown of atmospheric-pressure air by voltage pulses with an ∼0.5-μs front duration

Results are presented from experiments on the generation of runaway electron beams and X-ray emission in atmospheric-pressure air by using voltage pulses with an ∼0.5-μs front duration. It is shown that the use of small-curvature-radius spherical cathodes (or other cathodes with small curvature radii) decreases the intensity of the runaway electron beam and X-ray emission. It is found that, at sufficiently high voltages at the electrode gap (U{sub m} ∼ 100 kV), the gap breakdown, the formation of a spark channel, and the generation of a runaway electron beam occur over less than 10 ns. At high values of U{sub m} behind the anode that were reached by increasing the cathode size and the electrode gap length, a supershort avalanche electron beam with a full width at half-maximum (FWHM) of up to ∼100 ps was detected. At voltages of ∼50 kV, the second breakdown regime was revealed in which a runaway electron beam with an FWHM of ∼2 ns was generated, whereas the FWHM of the X-ray pulse increased to ∼100 ns. It is established that the energy of the bulk of runaway electrons decreases with increasing voltage front duration and is ⩽30 keV in the first regime and ⩽10more » keV in the second regime.« less
Authors:
;  [1]
  1. Russian Academy of Sciences, Institute of High-Current Electronics, Siberian Branch (Russian Federation)
Publication Date:
OSTI Identifier:
22472417
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 41; Journal Issue: 3; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AIR; ANODES; BREAKDOWN; CATHODES; ELECTRIC DISCHARGES; ELECTRIC POTENTIAL; ELECTRON BEAMS; EMISSION; KEV RANGE; RUNAWAY ELECTRONS; SPHERICAL CONFIGURATION; X RADIATION