Pilot Production And Advanced Development Of Large-Area Picosecond Photodetectors

We report pilot production and advanced development performance results achieved for Large Area Picosecond Photodetectors (LAPPD (TM)). The LAPPD (TM) is a microchannel plate (MCP) based photodetector, capable of imaging with single-photon sensitivity at high spatial and temporal resolutions in a hermetic package with an active area of 400 square centimeters(1). In December 2015, Incom Inc. completed installation of equipment and facilities for demonstration of early stage pilot production of LAPPD (TM). Initial fabrication trials commenced in January 2016. The "baseline" LAPPD (TM) employs an all-glass hermetic package with top and bottom plates and sidewalls made of borosilicate float glass. Signals are generated by a bi-alkali Na2KSb photocathode and amplified with a stacked chevron pair of "next generation" MCPs produced by applying resistive and emissive atomic layer deposition coatings to borosilicate glass capillary array (GCA) substrates(2,3,4,5) Signals are collected on RF strip-line anodes applied to the bottom plates which exit the detector via pin-free hermetic seals under the side walls(6). Prior tests show that LAPPD (TM) s have electron gains greater than 10(7), sub-millimeter space resolution for large pulses and several mm for single photons, time resolutions of 50 picoseconds for single photons, predicted resolution of less than 5 picoseconds for large pulses, high stability versus charge extraction, and good uniformity(7). LAPPD (TM) performance results for product produced during the first half of 2016 will be reviewed. Recent advances in the development of LAPPD (TM) will also be reviewed, as the baseline design is adapted to meet the requirements for a wide range of emerging application. These include a novel ceramic package design, ALD coated MCPs optimized to have a low temperature coefficient of resistance (TCR) and further advances to adapt the LAPPD (TM) for cryogenic applications using Liquid Argon (LAr). These developments will meet the needs for DOE-supported R&D for the Deep Underground Neutrino Experiment (DUNE), nuclear physics applications such as EIC, medical, homeland security and astronomical applications for direct and indirect photon detection.