Background reduction in a balloon-borne hard X-ray telescope

Abstract

We have been carrying out a series of balloon flight experiments using a large area proportional counter based (xenon filled) hard X-ray telescope and have studied in detail the spectral and temporal characteristics of several cosmic hard X-ray sources. The detector system uses multi-cell multi-layer configuration and for background reduction passive shielding, active anti-coincidence on three sides of the detector and mutual anti-coincidence for the active cells are employed. Further, K-gating technique is used to improve the energy resolution and detection efficiency. We present the effectiveness of the various background rejection techniques using a Monte-Carlo simulation and critically evaluate the possible improvements in the background rejection.