NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Voyager observations of lower hybrid noise in the Io plasma torus and anomalous plasma heating ratesA study of Voyager 1 electric field measurements obtained by the plasma wave instrument in the Io plasma torus has been carried out. A survey of the data has revealed the presence of persistent peaks in electric field spectra in the frequency range 100-600 Hz consistent with their identification as lower hybrid noise for a heavy-ion plasma of sulfur and oxygen. Typical wave intensities are 0.1 mV/m, and the spectra also show significant Doppler broadening, Delta omega/omega approximately 1. A theoretical analysis of lower hybrid wave generation by a bump-on-tail ring distribution of ions is given. The model is appropriate for plasmas with a superthermal pickup ion population present. A general methodology is used to demonstrate that the maximum plasma heating rate possible through anomalous wave-particle heat exchange is less than approximately 10 to the -14th ergs per cu cm per s. Although insufficient to meet the power requirement of the EUV-emitting warm torus, the heating rate is large enough to maintain a low-density (0.01-0.1 percent) superthermal electron population of keV electrons, which may lead to a small but significant anomalous ionization effect.
Document ID
19850043992
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Barbosa, D. D.
(California Univ. Los Angeles, CA, United States)
Coroniti, F. V.
(California, University Los Angeles, CA, United States)
Kurth, W. S.
(Iowa, University Iowa City, IA, United States)
Scarf, F. L.
(TRW, Inc. TRW Space and Technology Group, Redondo Beach, CA, United States)
Date Acquired
August 12, 2013
Publication Date
February 1, 1985
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 289
ISSN: 0004-637X
Subject Category
Lunar And Planetary Exploration
Accession Number
85A26143
Funding Number(s)
CONTRACT_GRANT: NGL-05-007-190
CONTRACT_GRANT: NSF ATM-81-19544
CONTRACT_GRANT: JPL-954012
CONTRACT_GRANT: NAGW-337
CONTRACT_GRANT: NASW-3504
CONTRACT_GRANT: JPL-954013
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available