Generation of broadband electrostatic noise by ion beam instabilities in the magnetotail. Progress report

Technical Report · Wed Jun 01 04:00:00 EDT 1983

OSTI ID:6572782

Grabbe, C L; Eastman, T E

Particle data from ISEE-1 sampled in the Earth's magnetotail show the presence of energetic ion beams in the boundary layer of the plasma sheet. A theory of instabilities driven by the beams is developed and compared with wave data sampled simultaneous to the particle data. We concluded that the ion beams generate broadband electrostatic bursts of noise. The electrostatic noise correlates well with the occurrence of the beams, and the spectrum is consistent with that predicted from a negative energy beam instability under magnetotail conditions. The theory predicts that a spectrum of growing waves can be driven for frequencies from .001 omega pe up to omega pe, the electron plasma frequency, with a spectral peak typically under .01 omega pe or lower, in agreement with the wave data. Furthermore, as one moves away from the source region perpendicular to the magnetic field, the high frequency components of the observed wave spectra are predicted to gradually disappear, leaving the low frequency part of the spectrum, also as is observed. Evidence is given for significant pitch-angle scattering of the beams by the broadband electrostatic noise leading to more isotropic ion distributions.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy
• OSTI ID: 6572782
• Report Number(s): AD-A-140809/5
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAMS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRONS
ELECTROSTATICS
ELEMENTARY PARTICLES
FERMIONS
ION BEAMS
LEPTONS
MAGNETIC FIELDS
MAGNETOSPHERE
MAGNETOTAIL
NOISE
PLASMA SHEET
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SHEETS
SPECTRA
STABILITY
TRANSPORT