NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mass loading and velocity diffusion models for heavy pickup ions at comet Grigg-SkjellerupWe compare model predictions of cometary water group ion densities and the solar wind slow down with measurements made by the Giotto Johnstone plasma analyzer implanted ion sensor at the encounter with comet Grigg-Skjellerup (G-S) on July 10, 1992. The observed slope of the ion density profile on approach to the comet is unexpectedly steep. Possible explanations for this are discussed. We present also a preliminary investigation of the quasilinear velocity-space diffusion of the implanted heavy ion population at G-S using a transport equation including souce, convection, adiabatic compression, and velocity diffusion terms. Resulting distributions are anisotropic, in agreement with observations. We consider theoretically the waves that may be generated by the diffusion process for the observed solar wind conditions. At initial ion injections, waves are generated at omega approximately Omega(sub i) the ion gyrofrequency, and lower frequencies are predicted for diffusion toward a bispherical shell.
Document ID
19950046628
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Huddleston, D. E.
(Jet Propulsion Lab. California Inst. of Tech., Pasadena, CA, United States)
Coates, A. J.
(University Coll. London, United Kingdom)
Johnstone, A. D.
(University Coll. London, United Kingdom)
Neubauer, Fritz M.
(Cologne Univ. Cologne, Germany)
Date Acquired
August 16, 2013
Publication Date
December 1, 1993
Publication Information
Publication: Journal of Geophysical Research
Volume: 98
Issue: A12
ISSN: 0148-0227
Subject Category
Astrophysics
Accession Number
95A78227
Distribution Limits
Public
Copyright
Other

Available Downloads

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