The HEAO-B Monitor Proportional Counter Instrument

The Monitor Proportional Counter Instrument for the HEAO-B X-Ray Telescope satelliteb is designed to observe celestial X-ray sources in the range of 1 to 20 keV with intensities exceeding 2 × 10-4 Crab. It provides both spectral and temporal data, to complement the data from the other HEAO-B instruments, to compare with observations from previous flights, as well as to allow detailed study of time variant X-ray phenomena. The basic detector is a large area proportional counter system, consisting of two counters, high voltage power supplies and pre-amplifiers, mounted behind a collimator with a 2/3 degree square field of view. The signal processing, power distribution and control electronics are contained in a separate unit, which includes circuitry to perform pulse height analysis, background rejection, time interval measurement, redundancy switching and control, housekeeping and telemetry interfacing.