Cross strip imaging anodes for microchannel plate detectors

We have developed a novel microchannel plate readout scheme, the cross strip anode. The cross strip anode has a coarse (0.5 mm) multilayer metal and ceramic cross strip pattern that encodes event positions by direct sensing of the charge on each strip and subsequent determination of the charge cloud centroid for each event. Event position encoding is accomplished with chip level preamplifiers on the anode, subsequent analog-to-digital conversion of individual strip charge values, and a software centroid determination. We find that the spatial resolution (<7 μm) is sufficient to resolve 12-μm microchannel plate pores. The cross strip anode can achieve this resolution while using low microchannel plate gain (≈5×10⁶ ), thus increasing the local counting rate capacity and overall lifetime of the microchannel plate detector system. The image linearity is good enough (<5 μm) to enable distortions in the microchannel plate hexagonal multifiber boundaries to be seen. We also discuss plans for custom chip electronics development so that encoding may be accomplished at photon counting rates >1 MHz and with low-power consumption (~2 W) that is suitable for applications in space astrophysics