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Title: Three-dimensional electromagnetic Monte Carlo particle-in-cell simulations of critical ionization velocity experiments in space

Abstract

Although the existence of the critical ionization velocity (CIV) is known from laboratory experiments, no agreement has been reached as to whether CIV exists in the natural space environment. In this paper the authors move towards more realistic models of CIV and present the first fully three-dimensional, electromagnetic particle-in-cell Monte-Carlo collision (PIC-MCC) simulations of typical space-based CIV experiments. In their model, the released neutral gas is taken to be a spherical cloud traveling across a magnetized ambient plasma. Simulations are performed for neutral clouds with various sizes and densities. The effects of the cloud parameters on ionization yield, wave energy growth, electron heating, momentum coupling, and the three-dimensional structure of the newly ionized plasma are discussed. The simulations suggest that the quantitative characteristics of momentum transfers among the ion beam, neutral cloud, and plasma waves is the key indicator of whether CIV can occur in space. The missing factors in space-based CIV experiments may be the conditions necessary for a continuous enhancement of the beam ion momentum. For a typical shaped charge release experiment, favorable CIV conditions may exist only in a very narrow, intermediate spatial region some distance from the release point due to the effects of the cloudmore » density and size. When CIV does occur, the newly ionized plasma from the cloud forms a very complex structure due to the combined forces from the geomagnetic field, the motion induced emf, and the polarization. Hence the detection of CIV also critically depends on the sensor location. 32 refs., 8 figs., 2 tabs.« less

Authors:
 [1];  [2];  [1]
  1. California Institute of Technology, Pasadena, CA (United States)
  2. Northeastern Univ., Boston, MA (United States)
Publication Date:
OSTI Identifier:
254453
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research
Additional Journal Information:
Journal Volume: 101; Journal Issue: A1; Other Information: PBD: 1 Jan 1996
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; EARTH MAGNETOSPHERE; GAS INJECTION; ATOMS; CRITICAL VELOCITY; IONIZATION; MONTE CARLO METHOD; COMPUTERIZED SIMULATION

Citation Formats

Wang, J, Biasca, R, and Liewer, P C. Three-dimensional electromagnetic Monte Carlo particle-in-cell simulations of critical ionization velocity experiments in space. United States: N. p., 1996. Web. doi:10.1029/95JA02312.
Wang, J, Biasca, R, & Liewer, P C. Three-dimensional electromagnetic Monte Carlo particle-in-cell simulations of critical ionization velocity experiments in space. United States. doi:10.1029/95JA02312.
Wang, J, Biasca, R, and Liewer, P C. Mon . "Three-dimensional electromagnetic Monte Carlo particle-in-cell simulations of critical ionization velocity experiments in space". United States. doi:10.1029/95JA02312.
@article{osti_254453,
title = {Three-dimensional electromagnetic Monte Carlo particle-in-cell simulations of critical ionization velocity experiments in space},
author = {Wang, J and Biasca, R and Liewer, P C},
abstractNote = {Although the existence of the critical ionization velocity (CIV) is known from laboratory experiments, no agreement has been reached as to whether CIV exists in the natural space environment. In this paper the authors move towards more realistic models of CIV and present the first fully three-dimensional, electromagnetic particle-in-cell Monte-Carlo collision (PIC-MCC) simulations of typical space-based CIV experiments. In their model, the released neutral gas is taken to be a spherical cloud traveling across a magnetized ambient plasma. Simulations are performed for neutral clouds with various sizes and densities. The effects of the cloud parameters on ionization yield, wave energy growth, electron heating, momentum coupling, and the three-dimensional structure of the newly ionized plasma are discussed. The simulations suggest that the quantitative characteristics of momentum transfers among the ion beam, neutral cloud, and plasma waves is the key indicator of whether CIV can occur in space. The missing factors in space-based CIV experiments may be the conditions necessary for a continuous enhancement of the beam ion momentum. For a typical shaped charge release experiment, favorable CIV conditions may exist only in a very narrow, intermediate spatial region some distance from the release point due to the effects of the cloud density and size. When CIV does occur, the newly ionized plasma from the cloud forms a very complex structure due to the combined forces from the geomagnetic field, the motion induced emf, and the polarization. Hence the detection of CIV also critically depends on the sensor location. 32 refs., 8 figs., 2 tabs.},
doi = {10.1029/95JA02312},
journal = {Journal of Geophysical Research},
number = A1,
volume = 101,
place = {United States},
year = {1996},
month = {1}
}