Plasma wave electric fields in the solar wind: Initial results from Helios 1

Journal Article · Tue Feb 01 04:00:00 EST 1977 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA082i004p00632· OSTI ID:7312369

Gurneti, D A; Anderson, R R

Plasma wave measurements provided by Helios 1 show that the electric field intensities in the solar wind are usually very low, much lower than those for comparable measurements near the earth, where particles moving upstream from the bow shock often cause large disturbances in the solar wind. The most commonly occurring plasma wave detected by Helios is a sporadic emission at frequencies from about 1 to 10 kHz, between the electron and ion plasma frequencies. These waves are though to be ion sound waves which are Doppler-shifted upward in frequency from below the ion plasma frequency. The maximum electric field intensity of these waves is a few hundred microvolts per meter. At higher frequencies, from about 20 to 100 kHz, electron plasma oscillations are detected at frequencies near the local electron plasma frequency. These electron plasma oscillations are more intense, with field strengths sometimes as large s a few millivolts per meter, but occur very infrequently. Both the ion sound waves and the electron plasma oscillations show a tendency to occur at higher frequencies closer to the sun but no pronounced variation in intensity with radial distance from the sun. In four cases, electron plasma oscillations have been found in association with type III radio bursts.

• Research Organization: Max-Planck-Institut fuer extraterrestrische Physik, 8046 Garching, West Germany
• OSTI ID: 7312369
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 82:4; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRIC FIELDS
ELECTRON DRIFT
HELIOS DEVICES
INTERPLANETARY SPACE
OPEN PLASMA DEVICES
PLASMA WAVES
Q DEVICES
SOLAR ACTIVITY
SOLAR WIND
SPACE
THERMONUCLEAR DEVICES