Compact ultraviolet imaging microchannel plate detectors using CODed Anode Converter (CODACON) readout systems

We describe imaging detectors (approximate to 350g, 0.7W), using microchannel plates (MCPs), for the ultraviolet imaging spectrometers on Planetary missions to Saturn and other planets. These detectors image by locating and counting individual photons one at a time, accumulating and storing the image in an external digital memory. The 1024 columns (spaced 25 mu) are coded by 10 bits and the 64 rows (spaced 100 mu) are coded by 6 bits. The detector head consists of a header-MCP housing, a chevron microchannel plate with a gain near 3x10(6), and a proximity focused anode called a code plate. The electronics consists of a low power high voltage power supply, a set of 16 hybrid low noise differential charge amps, 16 comparators, and 16 latches. A miniature digital buffer memory utilizes a field programmable gate array. We describe the theory and performance of the two dimensional CODACON.