Paper presented at the EGS General Assembly, 21-25, April, 1997, Vienna, Austria
The temperature of coronal electrons is classically derived from the ratio of optical line amplitudes that describe the temperature dependent charge distribution of suitable ion species. The availability of solar wind in-situ mass spectrometry has extended this method towards higher coronal altitudes and towards the determination of temperature gradients. With the high sensitivity of the ion charge spectrometer CELIAS-CTOF on SOHO the method could be used to study temperature variabiliy down to the length of an instrument cycle of 5 minutes: this improvement by about an order of magnitude demonstrated with Fe ion charge spectra adds fast temperature profiles to the diagnostics of coronal fine structure.