High-dynamic-range MCP structures

摘要

Abstract: A report is given on the development of a new high-dynamic-range two-stage multianode microchannel array (MAMA) imaging tube designed for improved high count rate performance at FUV and EUV wavelengths. The new two-stage MAMA tube employs two 25 mm diameter format MCPs placed in tandem with a small gap between the plates. The front (input) MCP is designed to be a low-gain converter plate that supports an opaque photocathode and converts the detected photons to electrons, while the second (output) MCP is of higher conductivity and thus maintains the overall gain of the multiplier at high count rates. The second MCP is mounted in proximity focus with a (224 $MUL 960) pixel fine-fine coincidence MAMA array for high-spatial-resolution imaging studies. The applied voltage across each MCP can be controlled independently. A report is given of the gain and dynamic range performance characteristics of the two-stage MAMA tube in two different configurations: first, with the output MCP having moderate conductivity (of the order of magnitude 100 M approximately ega@); and second, with the output MCP having very high conductivity (of the order of magnitude 2 M approximately ega@). These results are compared and contrasted with those of the more conventional MAMA tube configuration, which employs a single high-gain curved-channel MCP. !18