Amplification of critical velocity ionization by a pulsed neutral beam

Journal Article · Tue May 01 04:00:00 EDT 1990 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL017i006p00737· OSTI ID:6485672

Lai, S T; Murad, E ^[1]; McNeil, W J ^[2]

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1. Geophysics Lab., Hanscom Air Force Base, MA (USA)
2. Radex, Inc., Bedford, MA (USA)

Numerical results of computer simulations on critical ionization velocity (CIV) discharges in pulsed neutral beams are presented. In a typical CIV scenario, neutral molecules as well as newly created ions are traveling across the ambient magnetic field. The ions slow down as they transfer kinetic energy to the electrons via plasma waves. For a single pulse of neutral gas, there is a finite contact time between the beam and the plasma; the contact time is governed by the length of the pulse and the velocity of neutrals. The injection of multiple pulsed neutral beam into a magnetized plasma has the advantage that succeeding pulses may extend the effective contact time of a single pulse. Using the particle-in-cell method of computer simulations, the authors show a detailed time history of the CIV process as a result of the interplay between plasma (wave-particle) interactions and collisional (ionization, charge exchange) processes. It is found that ions slowing down and lagging behind the pulses can still contribute to electron heating. Simulation results show that CIV in a multiple pulsed beam is more efficient than that in a single continuous pulse.

• OSTI ID: 6485672
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 17:6; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM INJECTION
BEAM-PLASMA SYSTEMS
CHARGE EXCHANGE
COLLISIONS
COMPUTERIZED SIMULATION
EARTH ATMOSPHERE
INSTABILITY
IONIZATION
IONOSPHERE
NEUTRAL PARTICLES
PARTICLES
PLANETARY IONOSPHERES
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
PULSES
SIMULATION
TWO-STREAM INSTABILITY