Monitoring of hard X-ray transient sources in the energy 20-100 keV

Abstract

A hard X-ray camera is presented, which achieves X-ray position sensing using a thin inorganic scintillator viewed by a bank of photomultiplier tubes. The use of a single thin NaI or CsI scintillation crystal is proposed, in addition to a simple coded mask for imaging the sky on to the detector to provide high angular resolution and large sky coverage. A spatial resolution of less than 1 mm can be obtained, and for a detection area of 200 sq cm in the energy range of 20-100 keV, the sensitivity of the instrument is found to be about 0.005 photons per sq cm per sec for the detection of a source at a 5 sigma level during 30 minutes of operation.