Study on the improvement of the 20-inch microchannel plate photomultiplier tubes for neutrino detector

Abstract

The 20-inch MCP-PMT employs microchannel plates (MCP) as the electron multiplier unlike the traditional photomultiplier tubes (PMTs) with the dynode structure. According to the performance requirements for 20-inch PMTs to be used in the Hyper-Kamiokande (Hyper-K) project, North Night Vision Technology Co., Ltd. (NNVT) developed a novel 20-inch MCP-PMT based on the modification of the 20-inch MCP-PMT used for the Jiangmen Underground Neutrino Observatory by optimizing the design of the focusing electrode structure, the fabrication of the photocathode, and the other processes. The performance of the new NNVT 20-inch MCP-PMTs was evaluated and compared with respect to time resolution and noise. It was found that the transit time spread of the novel type is lower than 4 ns and the dark count rate is lower than 15 kHz. Compared to the previous model, the novel 20-inch MCP-PMT presents enhanced performance for time resolution and noise that is promising for its use in high-energy physics applications such as neutrino detection.