Sec. X instrumentatiion of the future the x‐ray timing explorer

Near the end of this decade, the X‐ray Timing Explorer (XTE) will provide X‐ray astronomers with a tool of unprecedented sensitivity for the study of compact X‐ray sources. The principal instruments, a 1 m2 proportional counter array and a 2000 cm2 phoswich array, will view the sky through coaligned one‐degree collimators and provide high sensitivity over a 2‐200 keV energy range. During the course of each satellite orbit, the entire sky will be scrutinized by the sky monitor experiment to a sensitivity of 0.05 Crab.