High precision gamma-ray spectrometer PGS for Russian interplanetary mission to Mars

The high precision gamma-ray spectrometer (PGS) is scheduled to be launched on the Russian MARS mission in 1996, and to go into an elliptical polar orbit around Mars. The PGS consists of two high-purity germanium detectors, associated electronics, and a passive cooler and will be deployed from one of the solar panels. The PGS will measure nuclear gamma-ray emissions from the Martian surface, cosmic gamma-ray bursts, and the high-energy component of solar flares in the broad energy range from 50 keV to 8 MeV in 4096 energy channels. The first results are presented of development, integration and qualification of the instrument, both for the passive cooler and for the detector with spectrometric electronics.     

Fast spectroscopy of the 4 November 1978 gamma-ray burst

The Franco-Soviet Signe experiments on Venera 11 and Venera 12 allow a spectral analysis of gamma-ray bursts with a time resolution of 250 ms. Evidence is presented for i) short annihilation flashes of up to 20 photons cm⁻²s⁻¹ and ii) rapid variations of the continuum, from a study of the intense 4 November 1978 event.