Paper presented at the EGS General Assembly, 21-25, April, 1997, Vienna, Austria
Charge composition measurements have been reported so far for solar wind energies and for energies larger than a few hundred keV/n. With advanced instrumentation on several spacecraft this gap is now being closed. Onboard SOHO, the time-of-flight mass spectrometers STOF and HSTOF of the CELIAS experiment cover this intermediate energy range. The instruments determine the mass, energy and charge (charge upper limit in HSTOF) of each particle from 35 keV/q up to 700 keV/q (STOF). We report on charge composition measurements obtained during the first year of the SOHO mission for several impulsive and coronal mass ejection (CME) related solar energetic particle events.