In orbit performance and calibration of the Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA)

The Proportional Counter Array (PCA) is designed to perform mu-second timing of bright galactic sources and broad band, confusion limited, studies of faint extragalactic sources in the 2-60 keV X-ray band. The PCA was launched as part of the Rossi X-ray Timing Explorer (RXTE) satellite into a circular orbit of altitude 580 km and 23 degrees inclination on December 30, 1995. The mission contains three experiments: a set of large area Xenon proportional counters sensitive from 2 - 60 keV (Proportional Counter Array: PCA), a set of large area sodium iodide scintillators sensitive from 15 - 200 keV (High Energy X-ray Timing Experiment: HEXTE), and three wide field of view scanning detectors which mont tor most of the sky each orbit (All Sky Monitor: ASM). The goals of the mission are summarized by Swank et al.(1) We present performance and calibration data on the measured and predicted in-orbit background, energy response, relative and absolute timing performance, and the operational possibililities made available with the high performance Experiment Data System (EDS) designed and built by MIT.