Determination of the characteristics of the gamma-ray telescope Gamma-1

The performance of the French/Soviet 50-5000-MeV gamma-ray telescope Gamma- 1 is predicted on the basis of calibration measurements (using tagged gamma beams of energy up to 500 MeV from a synchrotron) and numerical simulations (of both the particle-telescope interaction and the instrument response). The results are presented in extensive graphs and discussed in detail; it is concluded that a source with a flux of 3 x 10 to the -7th/sq cm sec photons of energy 100 MeV or greater can be detected with 5sigma significance in 1 Msec of observations at the background level of Cygnus. (T.K.)