Analysis of the performance of square photomultiplier tubes with 6 µm pore microchannel plates

Microchannel plate (MCP) based photomultiplier tubes (PMT) are used in applications where sub nanosecond timing and/or the ability to work in strong magnetic fields are critical, such as inertial confinement fusion diagnostics or Cherenkov based particle identification systems. Both aspects are improved by reducing the size of the pores in the MCP. Results have previously been presented with the Photek MAPMT253, a 53×53 mm active area square PMT configured with 8×8 anode pads and 15 µm pore MCPs. Here we present results analyzing the performance of the first square PMTs that use 6 µm pore MCPs. The detectors will be evaluated for single photon timing accuracy, gain, uniformity, magnetic field susceptibility, and count rate capability compared to the standard device.