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

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/95JA02312· OSTI ID:254453

Wang, J ^[1]; Biasca, R ^[2]; Liewer, P C ^[1]

---

1. California Institute of Technology, Pasadena, CA (United States)
2. Northeastern Univ., Boston, MA (United States)

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.

• OSTI ID: 254453
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A1 Vol. 101; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ATOMS
COMPUTERIZED SIMULATION
CRITICAL VELOCITY
EARTH MAGNETOSPHERE
GAS INJECTION
IONIZATION
MONTE CARLO METHOD