Performance of a Gas Scintillation Proportional Counter Array for a High-Energy X-Ray Observatory

摘要

A focal plane array of high-pressure gas scintillation proportional counters (GSPC) for a High Energy X-Ray Observatory (HERO) has been developed at the Marshall Space Flight Center. The array consists of eight GSPCs and is a part of balloon-born payload scheduled to fly in May 2004. These detectors have an active area of ～ 20 cm~2 each, and are filled with a high pressure (10~6 Pa) xenon-helium mixture. Imaging is via crossed-grid position-sensitive phototubes sensitive in the UV region. The performance of the GSPC is well matched to that of the telescope's x-ray optics which have response to 75 keV and a focal spot size of ～ 0.5 mm. The detector's energy resolution, 5.0% FWHM at 60 keV, is adequate for resolving the broad spectral lines of astrophysical importance and for accurate continuum measurements. Results of the ground detector array testing are presented.