Development of Gen-II LAPPDTMSystems For Nuclear Physics Experiments

The 2015 NSAC Long-Range Plan for Nuclear Science recommends an Initiative for “vigorous detector R&D in support of the neutrinoless double-beta-decay program and the Electron Ion Collider EIC. Both programs could extend future physics reach with the availability of ultra-fast time-of-flight photodetectors with high spatial and temporal resolution manufactured in a robust and cost-effective package. The Gen-II program focuses on three initiatives; a) capacitive-coupling anodes that use either a pixelated or stripline readout board suitable for high fluence applications, b) robust ceramic body package, and c) development of alternative fabrication means for low cost high volume production with the University of Chicago.Proof-of-concept was demonstrated in Phase I for robust hermetically-sealed ceramic packages with a capacitively-coupled anode. The Phase II program has produced two fully functional sealed Gen-II ceramic LAPPDTM incorporating high quantum efficiency (QE) bialkali photocathodes produced by the same transfer process and facility used in the Incom baseline (Gen-I) process.Zeramic metallization techniques co-developed with the University of Chicago in conjunction with advanced characterization and in-process quality control have led to robust hermetic sealing processes. The remaining tasks for the Incom Gen-II program are to supply commercially-produced 20cm x 20cm micro- channel-plate based photodetectors with sub-mm spatial resolution and single-photon time resolution in the range of 30-60 psec. These second generation devices enable an anode structure easily patterned to the user’s needs. This proposed Phase IIA Sequential SBIR will address the need for continued R&D to demonstrate repeatable production of Gen-II tiles with good QE, to characterize performance with application-specific capacitively- coupled readout configurations, to enable characterization of performance and lifetime testing, and, to demonstrate feasibility for pilot production and a pathway for lower-cost high-yield manufacturing of Gen-II devices. Phase II will support Gen-II LAPPDTMs with both stripline (for a low electronic channel count) and pixelated (pad) anodes (for high occupancy at colliders) using capacitive-coupling through the anode base. UChicago will continue development of advanced manufacturing techniques, including air-transfer/in-situ PC batch processing. As Incom exercises the sealing processes in both sealing tanks, extended-spectrum windows including fused silica and sapphire will be used for sealing. The University of Chicago group will also continue detailed characterization of the inside-out capacitively-coupled Gen-II detectors. Incom will expand its measurement and test capability for Gen-II tiles with a dedicated Gen-II LAPPDTM lifetime testing system. Collaborative efforts with early adopters at National Laboratories, agencies, and universities who have participated in Incom Measurement and Test Workshops have led to 10 Gen-I tiles having been sold.Shipments of the first prototype Gen-II modules are expected this year.