Wave generation and particle transport in the plasma sheet and boundary layer. Semiannual report

Technical Report · Sun Mar 01 04:00:00 EST 1987

OSTI ID:6481699

Dusenbery, P B

The one and two ion beam instability was considered as a possible explanation for the observations of broadband electrostatic noise in the plasma sheet region of the geomagnetic tail. When only hot streaming plasma sheet boundary layer ions were present, no broadband waves were excited. Cold, streaming ionospheric ions can generate electrostatic broadband waves propagating in the slow beam-acoustic mode, but the growth rates of the waves were significantly enhanced when warm boundary layer ions were presented. (Both the slow and fast beam-acoustic modes can be excited, depending on the relative ion drift.) This mode predicted that the wave intensity of the broadband noise should peak in the plasma sheet boundary layer (PSBL). Observations of less intense electrostatic waves in the lobes and plasma sheet were likely a result of the absence of warm ion beams or large ion temperatures, respectively, which resulted in smaller growth rates. The model dependence of the ion beam instability has also been studied. For cold and warm ions streaming in the same direction, researchers found wave growth peaked for wave normal angles theta = 0 deg. and wave frequencies approx. 0.1 x the electron plasma frequency. However, for anti-parallel streaming cold and warm ions, wave growth peaks near theta = 90 deg. and wave frequencies were an order of magnitude smaller.

• Research Organization: Colorado Univ., Boulder, (USA). Cooperative Inst. for Research in Environmental Sciences
• OSTI ID: 6481699
• Report Number(s): N-87-19104; NASA-CR-180216; NAS-1.26:180216
• Country of Publication: United States
• Language: English

Related Subjects

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Ionospheric
& Magetospheric Phenomena
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700107 -- Fusion Energy-- Plasma Research-- Instabilities
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAMS
BOUNDARY LAYERS
DATA
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTROSTATICS
EXPERIMENTAL DATA
HYDROMAGNETIC WAVES
INFORMATION
INSTABILITY
ION BEAMS
IONOSPHERE
LAYERS
MATHEMATICAL MODELS
NOISE
NUMERICAL DATA
PLANETARY IONOSPHERES
PLASMA SHEET
WAVE PROPAGATION