K.-H. Mühlhäuser

TL;DR: In this paper, it was found that a strong anisotropy in the core of proton distributions, with a temperature that is larger perpendicular rather than parallel to the magnetic field, is a persistent feature of high-speed streams, becoming most pronounced in the perihelion, or about 0.3 AU.

TL;DR: In this article, a helios solar probe survey of solar wind helium ion velocity distributions and derived parameters between 0.3 and 1 AU is presented, where the role of Coulomb collisions in limiting differential ion speeds and the ion temperature ratio is investigated.

TL;DR: A comparison between Solwind observations of coronal mass ejections (CME's) and Helios 1 observations of interplanetary shocks during 1979-1982 indicates that 72 percent of the shocks were associated with large, low-latitude mass ejection on the nearby limb.

TL;DR: In this paper, the shapes of three typical electron distribution functions, which have been observed by Helios 2 in the solar wind, are analyzed and compared with theoretical predictions, and the main results are as follows: (1) for each distribution function we may discern a break, i.e., a sudden change in the slope of the distribution function, separating the "core" at lower energies from the "halo" at larger energies, and (2) for the anisotropic distributions a significant break is observed in velocity directions opposite to the strahl and perpendicular to it

TL;DR: In this paper, the first part of the Helios-1 mission was used to study the solar corona and the solar wind during the period between 0.3 and 1 AU and the separation of proton double streams and alpha-particles.