Large Area Multi-Anode MCP-PMT for High Rate Applications Phase II

Nuclear physics (NP) research has a need for devices to detect, analyze, and track photons, charged particles, and neutral particles such as neutrons, neutrinos, and single atoms. Particle Identification (PID) subsystems, often operating in magnetic fields >1.5 Tesla, require highly segmented (2-3 mm pixel) photodetectors with high gain, low intrinsic background, and high photocathode efficiency to support the high rates found in noisy radiation environments. Large Area Picosecond Photo Detectors (LAPPD™) currently being commercialized by Incom, Inc. has demonstrated many of the needed requirements, however, there is still much development and optimization needed for LAPPD™ to be a candidate for these applications. Development and demonstration of a pixelated readout is essential for Electron Ion Collider (EIC) R&D efforts and can potentially provide an upgrade option for current Nuclear Physics PID subsystems. The development of the High Rate Picosecond Photon Detector (HRPPD) was initiated by Incom Inc. under DOE NP Phase I SBIR project (award DE-SC0020578) to fulfill specific requirements on photosensors to have a pixelated readout with 3 mm x 3 mm pixel size and perform at high rates (200 kHz/cm2) in a 2-3 Tesla magnetic field as exemplified by the EIC collaboration, and other NP programs. Realization of these features in 20 cm x 20 cm form factor LAPPD™ currently being commercialized by Incom Inc. is rather challenging although LAPPD has already demonstrated picosecond timing, high gain, low noise and high Quantum Efficiency (QE). In order to meet these needs, a new direct readout anode was demonstrated in Phase I to offer improved signal to noise compared to alternative approaches. Because of the complexity the technical development for this novel anode, it was decided to prototype it initially using a smaller 10 cm x 10 cm form before scaling up to full size (20 cm X 20 cm) LAPPD size. Over the course of Phase I project we have demonstrated feasibility of directly coupled 3 mm x 3 mm anode readout; developed 10 cm x 10 cm ALD functionalized MCPs with 10-micron pores for better timing and magnetic field tolerance and tested a fully functional open face High Rate Picosecond Photo Detector (HRPPD) package. The main objective of this Phase II project will be to demonstrate fully functional sealed HRPPD suitable for pilot production, test and evaluate prototype HRPPD in practical beamline trials. This will be realized in the following steps. Performing multiple sealing trials with HRPPD packages. Based on our experience with sealing 20 cm x 20 cm LAPPDs, multiple iterations of 10 cm x 10 cm detector packages will used to find an optimal sidewall geometry and metallization. Sealing HRPPD sidewalls to an entry window will be used to evaluate the designs with a goal of 80% sealing yield. Development of a reliable production process for large area 10-micron pore MCPs. As mentioned above under Phase I project, 108 mm x 108 mm 10-micron ALD-GCA-MCPs have been produced. However, the production yield for these GCA-ALD-MCPs was rather low due to the need to refine the production of large format 10-micron pore. In this Phase II we will increase yields and quality of larger format 10-micron pore MCPs by improving GCA fusing process and optimizing ALD process. Performing sealing trials with a complete MCP stack. Several sealing trials with a complete detector package will be initiated in a dedicated Integration and Sealing Tank. These fully functioning detectors will have a standard bi-alkali photocathode, a pair of 10-micron pore ALD-GCA-MCPs, and a pixelated or capacitively coupled readout. Characterization of HRPPD. In order to characterize the HRPPD, a dedicated readout board will be designed. Quantum Efficiency, gain, timing and spatial resolution, and the high-rate capability of HRPPD will be measured in a dedicated setup. Magnetic Field Tolerance HRPPD performance at high magnetic fields (up to 3T) will be evaluated. LAPPD™ and the HRPPD will enable new techniques in HEP, homeland security (non-proliferation) sensors to screen vehicles and cargo for Special Nuclear Materials (SNMs) and scientific detectors for astrophysics, time-of-flight mass spectrometry and medical imaging products including detectors for positron emission tomography (PET scanning) that are not accessible with conventional small area MCP-PMTs.