Two-Dimensional Simulations of a Charge-Neutral Plasma Beam Injected into a Transverse Magnetic Field
Abstract
It has been suggested that a charge-neutral beam consisting of ions and electrons may serve as an alternate to the plasma contractor for collecting electrons from the ionosphere. The collecting area of the beam would be determined by the distance it can penetrate the local magnetic field. A charge- neutral beam can transverse a magnetic field by virtue of collective effects for the proper parameter regime. This phenomenon is studied using a two-dimensional (three-velocity) electrostatic code. A polarization electric field forms across the beam as it penetrates the magnetic field. In vacuum the beam penetrates 4.5 sub i into the field, rho a gyroradius of a beam ion traveling at injection velocity. Loss of ions from the polarization layer produces a net electron current in the beam. The beam curves slightly due to the resulting j x B force. Injection into a tenuous plasma with a plasma-to-beam density ratio of 1/100 shortens the penetration length to 2.7 rho. The plasma partially shields the polarization field of the beam. Consequently, more beams ions are lost. The net beam current is enhanced resulting in a more pronounced curvature. Injection into a marginally dense plasma with a density ratio of 1/10 results in a pronounced deflection of the beam. Keywords: Spacecraft charging.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1989
- Accession Number
- ADA217079
Entities
People
- P. L. Pritchett
- W. A. Livesey
Organizations
- University of California, Los Angeles