Position sensing using pico-second timing with Micro-Channel Plate devices and waveform sampling

Micro-Channel Plate devices (MCP) provide fast signals with rise-times in the 100 ps range, allowing a measurement of the time-of-arrival of light pulses with a few pico-seconds accuracy using either constant fraction discrimination followed by time-to-digital conversion, or waveform sampling processed after digitization. The coupling of the MCP anode plane to 50 Omega transmission lines allows both a precise time measurement and additionally the potential for a position measurement with an accuracy of a few hundred microns for large-area devices. We present position measurement results obtained with MCPs from Photonis, 10-cm transmission lines, and a calibrated laser source followed by sampling and digitization, and waveform analysis. A detailed simulation of the transmission lines is presented. We compare the measured position resolution for two identical setups but with MCPs of different pore diameters: 25 and 10 microns. Simulation results are also presented for transmission lines up to 1-m in length.