Paper presented at the Fall Meeting of the Swiss Physical Society, Zürich, Switzerland, (1996).
Matter flowing away from the solar surface becomes highly ionized in the corona (approx. 106 K) by collisions with electrons. Due to the decreasing electron density with increasing distance from the solar surface, the charge state distributions freeze and remain unaltered throughout the interplanetary medium. This is why charge spectra measured at 1 AU are a valuable diagnostic tool for temperature and density variations in the inner solar corona. Preliminary results of iron charge spectra obtained from the SOHO CELIAS CTOF mass spectrometer indicate a patchy structure of the corona at scales of approx. 104 km.