Magnetic field effects on spatial relaxation of swarm particles in the idealized steady-state Townsend experiment
- School of Physics, University of Sydney, NSW 2006 (Australia)
- School of Mathematical and Physical Sciences, James Cook University, QLD 4810 (Australia)
The effect of a magnetic field at right angles to an electric field on spatial relaxation of a swarm of charged particles emitted by a plane source into a gas--the idealized steady-state Townsend experiment--is examined. The Boltzmann equation is solved using an adaptation of the 'two-temperature' moment method, involving a Burnett function representation of the velocity distribution function, a technique which is valid for charged particles of arbitrary mass and is intrinsically of a 'multiterm' nature. Results are presented for electrons in model and real gases, and are benchmarked against an exact analytical solution of the Boltzmann equation for a particular collision model. The application of a magnetic field significantly alters the relaxation profiles: in general, it can both enhance or retard spatial relaxation of transport properties. For methane gas, a multiterm analysis is essential to correctly account for the relaxation near the source, even though a two-term approximation may be sufficient when the magnetic field is sufficiently strong and hydrodynamic conditions dominate.
- OSTI ID:
- 20860811
- Journal Information:
- Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Vol. 74, Issue 2; Other Information: DOI: 10.1103/PhysRevE.74.026405; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-651X
- Country of Publication:
- United States
- Language:
- English
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