The HEAO-B Imaging Proportional Counter Design

The HEAO-B Imaging Proportional Counter is an X-ray imaging instrument designed for use in an orbiting observatory. It measures the spatial location and energy of individual X-ray photons by the risetime method and pulse height analysis respectively. The IPC can locate 0.1 to 4keV photons to within 1mm, and provides five bits of energy information. The IPC also includes an in-flight calibration source and a gas control system that maintains the counter gas density constant to an accuracy of 0.25%.