Fast-timing microchannel plate photodetectors: Design, fabrication, and characterization.

We report a detailed design, fabrication, and characterization of 6 × 6 cm ² fast timing photodetectors based on next-generation microchannel plates (MCPs). The whole assembly is made of low-cost borosilicate glass materials and hermetically sealed with a bialkali photocathode in a vacuum. The flexible photodetector design provides the potential of modifying individual components as well as the entire configuration to fit for different applications. A series of prototype MCP-photodetectors were fabricated following a step-by-step process including functionalization of glass capillary array through atomic layer deposition, MCP baking and scrubbing, photocathode deposition, and hermetic thermo-compression sealing. The prototype MCP-photodetectors exhibit electron gains well beyond 10 ⁷ level with good relative uniformity. An excellent rise time of 439 ps, timing distribution root-mean-square at a single photoelectron mode of 105 ps, a timing resolution of 20 ps, and magnetic field tolerance up to 1.3 T were achieved for a photodetector with 10 µm pore size MCPs, comparing to that of 536 ps, 205 ps, 63 ps, and 0.7 T for the one with 20 µm pore size MCPs.