Imaging Microchannel Plate Detectors For XUV Sky Survey Experiments

We describe the development of microchannel plate detectors for the Wide Field Camera (WFC) XUV (50-300Å) sky survey experiment on ROSAT. A novel feature of the detector design is that the microchannel plates (MCPs) and their resistive anode readout are curved to the same radius as the WFC telescope focal surface. We show that curving the channel plates is not detrimental to gain uniformity. We describe the design of a curved resistive anode readout element and contrast our measurements of spatial resolution, global and local uniformity and temperature coefficient of resistance with the poor performance recently ascribed to resistive anodes in the literature. We present the first measurements of the quantum detection efficiency of a CsI-coated MCP in the wavelength range 67-256Å.