Whistler mode turbulence at earth's bow shock: generation via electron beams and ray path integrated amplification

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6025678

Tokar, R L

The Landau and cyclotron growth rates of whistler mode instabilities in the transition region of Earth's bow shock are calculated using three electron distribution functions measured by the fast plasma experiment on ISEE 2 and a model distribution that is a function of penetration into the shock. The beam velocity vector is directed toward the magnetosheath. The calculations show that the distributions spontaneously generate whistler mode waves with electromagnetic Landau resonance and/or cyclotron resonance contributing to wave growth. Ray paths and path-integrated growth rates for the waves are calculated using a planar bow shock model. Waves with frequencies between about 1 and 100 Hz with a wide range of wave normal angles are generated by the landau and anomolous cyclotron resonances. The ray paths for these waves are directed toward the magnetosheath. However, because the integrated growth rate is small the waves do not attain large amplitudes within the shock transition region. Waves with frequencies between about 30 and 150 Hz with a wide range of wave normal angles are generated by the normal cyclotron resonance. Waves generated near the center of the shock transition region in the frequency range from about 70 to 110 Hz attain large amplitudes. The ray paths for most of these waves are directed toward the solar wind, although some wave packets, due to solar wind convection, travel transverse to the shock normal. These wave packets grow to large amplitudes because they spend a long time in the growth region.

• Research Organization: Iowa Univ., Iowa City (USA)
• OSTI ID: 6025678
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CYCLOTRON RESONANCE
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
FLUCTUATIONS
FREQUENCY RANGE
HZ RANGE
LANDAU FLUCTUATIONS
LEPTONS
NOISE
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
RESONANCE
VARIATIONS
WAVE PROPAGATION
WHISTLERS