Xi’an Institute of Optics and Precision Mechanics of CAS is developing a novel MCP-PMT with 2 × 2 matrix anode pixels with a time resolution of picosecond level. It is composed of a cermet shell, bi-alkali photocathode, and V-type cascade MCP layers. In order to study the method of measuring the characteristics of such MCP-PMT with picosecond time resolution, we develop a PMT test system to test its performance.

A voltage divider resistor circuit for the MCP-PMT is designed to meet the requirements of both high gain and fast time response. The test system includes a picosecond laser source in the single-photon mode, a high-bandwidth oscilloscope, and another fast MCP-PMT as reference. Full waveforms of PMT signals are collected and analyzed offline. The overall system time error is 26 ps.

The test result shows that the gain of the MCP-PMT achieves 1 × 107. The transit time spread (TTS) of all channels is better than 60 ps (σ). The uniformity and crosstalk among adjacent channels are also studied by scanning each channel’s response along the photocathode plane.

The MCP-PMT shows excellent timing performance and the potential of achieving better spatial resolution by further pixelation.

The schematic of MCP-PMT. (Image by XIOPM)