Development of advanced photocathodes for LAPPD

Recently developed Large Area Picosecond Photo-Detectors (LAPPD) have a number of very attractive features not available in any other commercially available Micro-Channel Plate Photomultiplier Tubes (MCP-PMT), including a planar geometry with a large active area of up to 400 cm2, ~50 pS temporal resolution, few mm spatial resolution, and advanced microchannel plates (MCPs) offering very high gain, low noise and other benefits. A prime target application for LAPPD is to detect Cherenkov radiation, with a maximum emission in the ultraviolet-visible spectral range, for time of flight and particle identification. Developing photosensitive materials exhibiting higher sensitivity compared to standard and incorporating them into LAPPD, would add another attractive feature further differentiating LAPPD from the competition. Higher sensitivity allow detecting photons one-by-one with exceptional reliability enabling new techniques in HEP, homeland security, scientific detectors for astrophysics, electron microscopy, time-of-flight mass spectrometry, etc. that are not accessible with conventional small area MCP-PMTs. This Phase I Funding Opportunity addresses the need for R&D to develop for LAPPD photocathode materials exhibiting high photon sensitivity. Development of the photocathode materials with Quantum Efficiency (QE) exceeding 30% and incorporating those materials into LAPPDs will be the prime objective of this Phase I proposal. This will be accomplished through three key objectives: a) optimization of the current baseline photocathode, b) development of Li2CsSb, a novel, potentially high performing photocathode material, and c) development of UV-enhanced bi-alkali photocathodes with sharp long wavelength cutoffs.Large Area Picosecond Photo-Detectors (LAPPDs) with high QE (and Photon Detection Efficiency) will allow for detecting photons one-by-one with near-perfect reliability. They 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.