Cross-strip anodes for high-rate single-photon imaging

Novel microchannel plate (MCP) imaging detectors using cross strip (XS) anodes have been developed recently and demonstrated to be capable of position resolution better than ten microns, nanosecond timing accuracy, and event rates of greater than 3 × 10⁵ counts per second. These detectors use charge division and centroiding of MCP charge signals directed onto two orthogonal layers of sensing anode strips to encode event position, event time, and signal amplitude. In this paper, we describe measurements designed to understand the maximum possible event rates that such detectors are capable of handling. For these measurements, the signals from each strip (32 on each axis for the anode discussed here) are sent to a preamplifier ASIC that outputs shaped unipolar pulses with 40 ns rise time and 200 ns fall time, which are then digitized at 62.5 mega-samples per second and written to disk. Offline analysis is performed on long data records (up to 25 milliseconds) containing many individual events at event rates up to 10⁸ counts per second with different spatial distributions over the detector area. We present analysis algorithms and results on our measured ability to resolve events spatially and temporally as the event rate is increased. We also briefly discuss future plans to develop compact, fieldable systems based on this XS anode technology for a variety of applications, from astronomy to remote sensing.