Cross-strip anodes for microchannel plate detectors

The cross strip anode is a coarse (0.5 mm) multi-layer metal and ceramic cross strip pattern. Event positions are encoded by direct sensing of the charge on each strip and subsequent determination of the charge cloud centroid for each event. This event position encoding is accomplished with chip preamplifiers on the anode, subsequent analog to digital conversion of individual strip charge values and a software centroid determination. The spatial resolution (<5 mum) achieved for an 8 x 8mm anode is sufficient to resolve 7mum microchannel plate pores while using low MCP gain (approximate to2 X 106) in an MCP pair configuration. The image linearity is good enough to enable distortions in the microchannel plate pore pattern to be seen as well as dead and distorted pores. The low MCP gain will enhance the local counting rate capacity and overall lifetime of a microchannel plate detector system with cross strip readout. We discuss plans for fabrication of a 32mm x 32mm anode with custom chip electronics so that encoding may be accomplished at photon counting rates >1 MHz and with low power consumption (similar to2W) suitable for applications in space astrophysics.