Electron flux distribution of a flat X-ray spectrum
Very flat X-ray spectrum (gamma <= 2 below 80 keV) was detected at the
burst  maximum of 20 Aug 2002 flare.  Fitting of an isothermal
component plus a double power-law electron flux distribution  function
in the thick target model revealed the low energy cutoff of 80 keV
which would mean a gap between energies of the thermal plasma (T ~ 10 MK) 
and the injected  electrons. Assuming different shapes of electron
flux distribution below the low energy cutoff we investigate their
influence on the photon spectrum. The results are  discussed in the
frame of detectable changes in the RHESSI photon spectrum.