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Observations of Solar Wind Ion Charge Exchange in the Comet Halley Coma

Balsiger, H.; Ip, W. -H.; Goldstein, B. E. +5 more

Giotto Ion Mass Spectrometer/High Energy Range Spectrometer (IMS/HERS) observations of solar wind ions show charge exchange effects and solar wind compositional changes in the coma of Comet Halley. As the comet was approached, the He(2+) to proton density ratio increased from 2.5 percent in the solar wind to about 4 percent about 1 hr before close…

Densities and Abundances of Hot Cometary Ions in the Coma of P/Halley

Balsiger, H.; Ip, W. -H.; Goldstein, B. E. +3 more

The densities of the hot component in the ion population observed in the P/Halley coma by the ion mass spectrometer aboard the Giotto spacecraft has been recomputed, and the results are reported. Except for protons and H2(+), all densities are found to be at least an order of magnitude higher than predicted by the physicochemical model of Schmidt …

Sulfur-bearing Ions in the Ionosphere of Comet Halley

Reme, H.; Korth, A.; Lin, R. P. +3 more

This paper presents the radial density profiles of the ions corresponding to 35, 45, 47, and 47 amu, inside the ionopause of Comet Halley, obtained by the heavy ion analyzer PICCA on board the Giotto spacecraft. A photochemical model of the outflowing atmosphere/ionosphere, which emphasizes the sulfur chemistry in an H2O-dominated atmosphere, is u…