Optimization of spatial resolution and detection efficiency for photon/electron/neutron/ion counting detectors with Microchannel Plates and Quad Timepix readout

摘要

Although event counting detectors with Microchannel Plates (MCPs) were originally developed primarily for applications with low input fluxes, recent progress in readout electronics substantially extended their counting rate capabilities, while still maintaining very low dark count rates and no readout noise. Detection of many simultaneous events and operation at rates exceeding 100 MHz has been demonstrated with combination of MCPs and a Timepix readout. The spatial resolution in such devices can be an order of magnitude better than the 55 μm pixel size of Timepix chips when event centroiding is implemented. However, a compromise between spatial resolution and the number of accepted events has to be found for such detectors operating at high rates. Here we present an MCP/Timepix detector capable of simultaneous detection of an image with the highest spatial resolution of ~6.5 μm, but reduced number of counts and an image with all registered photons but reduced 55 μm spatial resolution. A compromise between detector resolution and the acquisition duty cycle is also discussed. It was confirmed that high spatial resolution can still be maintained through event centroiding even with 60% of pixels hit by more than one photon per acquisition frame.