A large area, high pressure, sealed, xenon-filled imaging proportional counter for applications in X-ray astronomy

There are now several applications in X-ray Astronomy which require sealed, imaging proportional counters of relatively large area. These include missions such as AXAF and XMM. These applications also require xenon at high pressure as the majority gas constituents to give adequate stopping power to prevent image blurring. An imaging proportional counter of this type is described with a sensitive area 30 cm square. The position resolution, linearity and energy resolution are described, and the factors limiting these parameters in large area imaging proportional counters are examined. (orig.)