High Resolution Electronics for a Position Sensitive MCP Delay-line Detector

Abstract

This paper presents a readout electronics getting high position resolution of the photon hit on the Micro-Channel Plate (MCP) Delay-line detector using FPGA-based Time to Digital Converters (TDC). The time measurement electronics obtain high performance of resolution better than 40ps (in RMS). There are two TDCs in each electronics module, while each TDC has five channels to deal with one MCP detector’ 1 start signal and four stop signals (each stop from one corner of the delay-line MCP). With a large dynamic range up to 1.32 second the readout system provides the hit time sequence – the arriving times of phonon. To separate the multi-hit events which mean more than one hit signal transmitting on the delay line, the dead time of the TDCs is designed to be shorter than 20 ns. The TDC and related digital circuits are implemented in a Xilinx low-end Artix-7 FPGA, which has a good balance between performance and cost. The digitized time data of all TDCs and channel number are gathered and then transmitted by USB 3.0 interface, with the speed of up to 1.6Gb/s and it also transmit commands from master PC to the TDC module. Finally, we used a spatial grating and X-ray source to test the detector system and a position resolution better than 0.1mm was obtained.