The directivity of hard X-ray radiation of solar flares detected by SNEG-2MZ

A systematic softening of the X-ray spectrum toward the center of the solar disk in the energy region above 50 keV is observed. The radiation spectra observed experimentally are compared with those calculated in terms of the thick target model taking into account the electron Coulomb scattering and the reflection of radiation from the photosphere. The comparison shows that the observed spectra softening toward the center of the solar disk is most likely to be due to the angular anisotropy of the accelerated electrons. The results obtained point to the acceleration of electrons with different angular distribution in different solar flares.