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Title: Simulation of the Plasma Afterglow in the Discharge Gap of a Subnanosecond Switch Based on an Open Discharge in Helium

Abstract

The phenomenon of subnanosecond electrical breakdown in a strong electric field observed in an open discharge in helium at pressures of 6–20 Torr can be used to create ultrafast plasma switches triggering into a conducting state for a time shorter than 1 ns. To evaluate the possible repetition rate of such a subnanosecond switch, it is interesting to study the decay dynamics of the plasma remaining in the discharge gap after ultrafast breakdown. In this paper, a kinetic model based on the particle-in-cell Monte Carlo collision method is used to study the dynamics of the plasma afterglow in the discharge gap of a subnanosecond switch operating with helium at a pressure of 6 Torr. The simulation results show that the radiative, collisional-radiative, and three-body collision recombination mechanisms significantly contribute to the afterglow decay only while the plasma density remains higher than 10{sup 12} cm{sup −3}; the main mechanism of the further plasma decay is diffusion of plasma particles onto the wall. Therefore, the effect of recombination in the plasma bulk is observed only during the first 10–20 μs of the afterglow. Over nearly the same time, plasma electrons become thermalized. The afterglow time can be substantially reduced by applying amore » positive voltage U{sub c} to the cathode. Since diffusive losses are limited by the ion mobility, the additional ion drift toward the wall significantly accelerates plasma decay. As U{sub c} increases from 0 to +500 V, the characteristic time of plasma decay is reduced from 35 to 10 μs.« less

Authors:
;  [1]
  1. Russian Academy of Sciences, Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation)
Publication Date:
OSTI Identifier:
22763275
Resource Type:
Journal Article
Journal Name:
Plasma Physics Reports
Additional Journal Information:
Journal Volume: 44; Journal Issue: 5; Other Information: Copyright (c) 2018 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-780X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AFTERGLOW; ATOM COLLISIONS; BREAKDOWN; ELECTRIC FIELDS; ELECTRICAL FAULTS; HELIUM; ION DRIFT; ION MOBILITY; MONTE CARLO METHOD; PLASMA DENSITY; PLASMA SWITCHES; THREE-BODY PROBLEM

Citation Formats

Alexandrov, A. L., E-mail: a-alex@itam.nsc.ru, and Schweigert, I. V. Simulation of the Plasma Afterglow in the Discharge Gap of a Subnanosecond Switch Based on an Open Discharge in Helium. United States: N. p., 2018. Web. doi:10.1134/S1063780X1805001X.
Alexandrov, A. L., E-mail: a-alex@itam.nsc.ru, & Schweigert, I. V. Simulation of the Plasma Afterglow in the Discharge Gap of a Subnanosecond Switch Based on an Open Discharge in Helium. United States. doi:10.1134/S1063780X1805001X.
Alexandrov, A. L., E-mail: a-alex@itam.nsc.ru, and Schweigert, I. V. Tue . "Simulation of the Plasma Afterglow in the Discharge Gap of a Subnanosecond Switch Based on an Open Discharge in Helium". United States. doi:10.1134/S1063780X1805001X.
@article{osti_22763275,
title = {Simulation of the Plasma Afterglow in the Discharge Gap of a Subnanosecond Switch Based on an Open Discharge in Helium},
author = {Alexandrov, A. L., E-mail: a-alex@itam.nsc.ru and Schweigert, I. V.},
abstractNote = {The phenomenon of subnanosecond electrical breakdown in a strong electric field observed in an open discharge in helium at pressures of 6–20 Torr can be used to create ultrafast plasma switches triggering into a conducting state for a time shorter than 1 ns. To evaluate the possible repetition rate of such a subnanosecond switch, it is interesting to study the decay dynamics of the plasma remaining in the discharge gap after ultrafast breakdown. In this paper, a kinetic model based on the particle-in-cell Monte Carlo collision method is used to study the dynamics of the plasma afterglow in the discharge gap of a subnanosecond switch operating with helium at a pressure of 6 Torr. The simulation results show that the radiative, collisional-radiative, and three-body collision recombination mechanisms significantly contribute to the afterglow decay only while the plasma density remains higher than 10{sup 12} cm{sup −3}; the main mechanism of the further plasma decay is diffusion of plasma particles onto the wall. Therefore, the effect of recombination in the plasma bulk is observed only during the first 10–20 μs of the afterglow. Over nearly the same time, plasma electrons become thermalized. The afterglow time can be substantially reduced by applying a positive voltage U{sub c} to the cathode. Since diffusive losses are limited by the ion mobility, the additional ion drift toward the wall significantly accelerates plasma decay. As U{sub c} increases from 0 to +500 V, the characteristic time of plasma decay is reduced from 35 to 10 μs.},
doi = {10.1134/S1063780X1805001X},
journal = {Plasma Physics Reports},
issn = {1063-780X},
number = 5,
volume = 44,
place = {United States},
year = {2018},
month = {5}
}