Plasma waves associated with the first AMPTE (Active Magnetosphere Particle Tracer Explorers) magnetotail barium release. Progress report

Technical Report · Tue May 20 04:00:00 EDT 1986

OSTI ID:5111678

Gurnett, D A; Anderson, R R; Bernhardt, P A; Luhr, H; Haerendel, G

Plasma waves observed during the March 12, 1985, AMPTE magnetotail barium release are described. Electron plasma oscillations provided local measurements of the plasma density during both the expansion and decay phases. Immediately after the explosion the electron density reached a peak of about -40000/cc and then started decreasing approximately as t to the -2.4 power as the cloud expanded. About 6 minutes after the explosion, the electron density suddenly began to increased, reached a secondary peak of about 240/cc, and then slowly decayed down to the pre-event level over a period of about 15 minutes. The density increase is believed to be caused by the collapse of the ion cloud into the diamagnetic cavity created by the initial expansion. The plasma-wave intensities observed during the entire event were quite low. In the diamagnetic cavity, electrostatic emissions were observed near the barium ion plasma frequency, and in another band at lower frequencies. A broadband burst of electrostatic noise was also observed at the boundary of the diamagnetic cavity. Except for electron-plasma oscillations, no significant wave activity was observed outside of the diamagnetic cavity.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy
• OSTI ID: 5111678
• Report Number(s): AD-A-170277/8/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
BARIUM
DIAMAGNETISM
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRON DENSITY
ELEMENTS
MAGNETISM
MAGNETOTAIL
METALS
PLASMA WAVES