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The helium isotopic ratio in the solar wind and ion fractionation in the corona by inefficient Coulomb drag

Bochsler, Peter; Bodmer, Roland

Using data obtained between 1991 and 1996 with the SWICS instrument (Solar Wind Ion Composition Spectrometer) aboard the Ulysses spacecraft, a long time average of the ((4) He / (3) He ) isotopic ratio of 2450 +/- 460 in coronal hole dominated solar wind is derived. To assess the influence of inefficient Coulomb friction in the inner corona and to…

Particle acceleration efficiency and MHD characteristics of CIR-related shocks

Mann, G.; Keppler, E.; Classen, H. -T.

During its southbound journey the Ulysses spacecraft crossed a series of corotating interaction regions (CIRs) building up due to the interaction of fast and slow solar wind streams. We analyse the forward and the reverse shocks marking off the 18 CIR encounters between July 1992 and December 1993. Our investigations look for a correlation between…

High latitude ULYSSES observations of CIR accelerated ions and electrons

Simnett, G. M.; Sayle, K. A.

From the comparison of the intensity maxima of ~ 1 MeV/nuc. ions with those of the 40-65 keV electrons and higher energy ions ( ~ 2-4 and 4-8 MeV/nuc.), during Ulysses' ascent to the solar south pole, 1992-1994, evidence has been found for the ~ 1 MeV/nuc. ions observed at high latitude by the Ulysses spacecraft to have originated at mid-latitudes…

Extreme-ultraviolet diagnostics of pick-up ions in regions close to the solar corona. I. Feasibility of new observations

Fichtner, Horst; Fahr, Hans-Joerg; Scherer, Horst

Recent investigations of pick-up ion data obtained with the AMPTE and the Ulysses spacecraft resulted in the discovery that, in contrast to previous expectation, pick-up ion velocity distribution can be anisotropic. Such anisotropy results from a smaller efficiency of pitch-angle scattering than usually assumed and translates into a larger scatter…