A Gas Scintillation Proportional Counter for the X-Ray Astronomy Satellite SAX

A driftless gas scintillation proportional counter is described. The instrument has several advantages over conventional GSPCs especially for applications at low x-ray energies (~0.l - 30 keV) and small dimensions such as imaging focal plane detectors for x-ray telescopes or concentrators. The x-ray astronomy satellite project SAX has such a requirement and an imaging GSPC of this configuration is presented in this context.