Optimization of high count rate event counting detector with Microchannel Plates and quad Timepix readout

摘要

Many high resolution event counting devices process one event at a time and cannot register simultaneous events. In this article a frame-based readout event counting detector consisting of a pair of MicroChannel Plates and a quad Timepix readout is described. More than 10~4 simultaneous events can be detected with a spatial resolution of ～55 μm, while ＞ 10~3 simultaneous events can be detected with ＜ 10 μm spatial resolution when event centroiding is implemented. The fast readout electronics is capable of processing ＞ 1200 frames/sec, while the global count rate of the detector can exceed 5 × 10~8 particles/s when no timing information on every particle is required. For the first generation Timepix readout, the timing resolution is limited by the Timepix clock to 10-20 ns. Optimization of the MCP gain, rear field voltage and Timepix threshold levels are crucial for the device performance and that is the main subject of this article. These devices can be very attractive for applications where the photon/electron/ioneutron counting with high spatial and temporal resolution is required, such as energy resolved neutron imaging, Time of Flight experiments in lidar applications, experiments on photoelec-tron spectroscopy and many others.