Giotto-IMS observations of ion flow velocities and temperatures outside the contact surface of Comet HalleyFluid parameters for He(++) ions obtained from the Giotto ion mass spectrometer are presented. Proton densities and velocities and thermal speeds of protons, alpha particles, and heavy ions in the hour before closest approach are discussed. A region of enhanced He(++) ion densities, and velocity, and decreased temperature is observed from 20:26 to 21:45. Sharp decreases in the proton density are observed at 23:30 and at 23:41. There is a relative flow velocity between alpha particles and oxygen ions of 30 km/sec during a period from 22:55 to 23:30; the difference in flow velocity is less than the experimental uncertainities. The flow properties of protons observed during this period are also discussed.
Document ID
19870015746
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Goldstein, B. E. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Neugebauer, M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Balsiger, H. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Drake, J. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Fuselier, S. A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Goldstein, R. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ip, WING-H. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Rettenmund, U. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Rosenbauer, H. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Schwenn, R. (Max-Planck-Inst. fuer Aeronomie Katlenburg-Lindau, Germany)
Date Acquired
September 5, 2013
Publication Date
December 1, 1986
Publication Information
Publication: ESA Proceedings of the 20th ESLAB Symposium on the Exploration of Halley's Comet. Volume 1: Plasma and Gas