Solar flare soft X-ray spectra from Diogeness observations

Diogeness was an uncollimated scanning flat crystal spectrometer observing solar flare X-ray spectra in four narrow wavelength bands in the vicinity of Ca xix, S xv and Si xiii He-like line ‘triplets’ around 3.18 Å, 5.04 Å and 6.65 Å. In two of the spectral channels, emission lines around the Ca xix 3.178 Å resonance line were scanned in opposite directions, being diffracted from precisely adjusted identical Quartz crystals mounted on a common shaft in a so-called Dopplerometer (tachometer) configuration. Observations of solar X-ray spectra made by Diogeness provide a direct diagnostic information on plasma characteristics during the impulsive flare energy release. We present a sample of events which occurred during the Diogeness operation time from August 16, 2001 to September 17, 2001.