Development of Large-Area MCP-PMT Photo-Detectors for a Precision Time-of-Flight System at the Fermilab Test Beam Facility

A system of Large Area Picosecond Photodetectors (LAPPD^TM) has been constructed at the Fermilab Test Beam Facility (FTBF) to measure charged particles in a time-of-flight configuration. Cherenkov photons produced by charged particles passing through the glass window induce signals that mark the particle's time-of-arrival and position at each LAPPD. A method for batch fabrication of LAPPDs developed at University of Chicago is described in detail. Four LAPPDs were instrumented into a time-of-flight system, three simultaneously, including one Generation-II capacitively-coupled LAPPD fabricated at University of Chicago. The time-of-flight system is designed with the intention of evolving into a permanent measurement system for the FTBF, providing users with a mass measurement of particles on an event-by-event basis. A draft procedure for analyzing charged particle data using LAPPDs is presented. The pion and kaon 1-sigma separation sensitivity is estimated to be 7-8 GeV/c at 5 m separation and 22-25 GeV/c at 45 m separation. Sensitivities are also projected, taking into account already identified design improvements that may be implemented in the next 1-5 years. A summary of the next-steps and a design of a permanent system is presented.