Microchannel plate operation at high count rates new results

We describe an experimental study of two distinct microchannel plate MCP detector con gurations with extended dynamic range First we report on measurements made with single MCPs of very low resistance k bonded to a Peltier cooler Stable reproducible operation for a rear cooled MCP with m diameter channels of length to diameter ratio was achieved for biases up to V At this point the MCP strip current was mA and the rate of internal heat generation W cm A maximum count rate of cm s limited by the available intensity of UV illumination was observed coupled to a dark noise count rate of less than cm s Second we describe a substantial up to fold improvement in count rate capability for two stage MCP multipliers incorporating plates with gold rather than nichrome electrodes We also present in support of the experimental study a thermal model of bonded conductively cooled MCPs which we use to determine critical parameters for stable detector operation