Suprathermal ions of solar and interstellar origin associated with the April 9-12, 2001, CMEs

Abstract

The distribution functions of suprathermal ions associated with the two interplanetary coronal mass ejections in the time period of April 9-12, 2001, are analyzed. The data on ions in the energy range 35-2000 keV/amu were recorded by the (Highly) Suprathermal Time-of-Flight (HSTOF/STOF) Spectrometer on board the Solar and Heliospheric Observatory (SOHO) at 1 AU. While the instrument passes the event the ion spectra undergo changes that correpond to the local plasma properties. In particular, there are significant differences between the spectra and the spatial distribution of singly charged interstellar ⁴He ⁺ pick-up ions and of solar wind ⁴He ²⁺ ions, respectively.