The Ability of Cos-B to Measure Gamma-Ray Bursts

The COS-B satellite for gamma-ray astronomy, launched on 7 August, 1975, features as part of the main instrument a 1.1 m², 10 mm thick, plastic scintillator for the vetoing of charged particle events. This detector which has an average effective area of 360 cm² for gamma rays in the interval 0.1 to 1 MeV has been instrumented to detect and record the temporal structure of cosmic gamma ray bursts. The instrument will be sensitive to gamma bursts down to 3% of the typical intensities measured by the Vela satellite system. The best time resolution achievable is 1.6 ms. The satellite will be placed in a 100 000 km eccentric orbit and with absolute timing accuracies of fractions of a millisecond achievable, a long base line is available for the triangulation of the source position, given comparable data from other satellites.