A system for investigating the properties of cosmic gamma radiation with energies above 1 MeV.

The paper gives the basic technical features of a gamma telescope whose chief recording element is a multilayered spark chamber with ferrite memory. The instrument was originally described by Galper et al. (1975). Multiwire proportional counters of sensitive area 224 x 224 mm serve as trigger counters. To eliminate background noise caused by charged particles, the telescope chamber is equipped with six anti-coincidence-connected scintillation counters made of polystyrene. Efficiency for recording gamma quanta was calculated to be 3.9% at 5 MeV and 8.6% at 100 MeV. Transmission of the telescope averaged over the isotropic spectrum of radiation with index 2,1 amounts to 12.5 sq cm ster. Accuracy in determination of angle of arrival of gamma quanta was calculated to be 9 and 3 deg for 10 MeV and 17 MeV particles, respectively.