Solar hard X-ray and ?-ray bursts observed by the sigma anti-coincidence shield aboard granat

Abstract

The anti-coincidence shield of the SIGMA telescope aboard GRANAT provides observations of solar X-ray and γ-ray bursts in the energy range 200 keV–15 MeV. The characteristics of the experiment are presented here as well as the observations of the solar bursts detected during the first year of operation. Among these events, two of these bursts associated respectively with a limb and a disk flare were observed with significant flux above 10 MeV. Advantage is taken of the experiment large detector area to examine fine time structures even at high energies (≥ 10 MeV).