Design of the large area MCP-PMT

Abstract This paper describes the design of the 8-inch and 20-inch photomultiplier tubes based on microchannel plates (MCP-PMT). In the large area MCP-PMT, the small MCPs replace the bulky dynode chain in the traditional large PMTs. Photoelectrons are electrostatically focused on MCPs. The MCP assembly, focusing electrodes as well as the supply voltages are carefully optimized to achieve a wide photosensitive area, high photon detection efficiency and good timing resolution.