Concerning the procedure of recovering the electron energy distribution function from the soft X-ray spectrum

In the course of experiments on electron-cyclotron resonance heating of plasma in the L-2M stellarator, it was found that, at high specific heating powers, the SXR spectrum was distorted in the entire photon energy range under study (from 1.5 to 15 keV). To determine the character of this distortion, a procedure was proposed for recovering the electron energy distribution function (EEDF) from soft X-ray (SXR) measurements. The SXR spectra were analyzed for different values of the specific heating power. Numerical calculations show that the edge plasma contributes insignificantly to the chord-averaged SXR spectrum. A conclusion is drawn on the applicability and accuracy of the procedure for recovering the EEDF at high specific heating powers.