T. Cremer, B.W. Adams, M. Aviles, C. Ertley, M.R. Foley, C. Hamel, A. Lyashenko, M.J. Minot, M.A. Popecki, M.E. Stochaj, W.A. Worstell, J.W. Elam, A.U. Mane, M. Gebhard, O.H. Siegmund
Keywords: microchannel plates, photodetector, electron amplification, particle detection, atomic layer deposition
Summary:Incom Inc. is developing and commercializing a new type of microchannel plate (MCP) electron multipliers. These new devices called “ALD-GCA-MCPs” and are made from glass capillary arrays (GCA), glass plates with a regular array of hollow glass capillaries that are functionalized using atomic layer deposition (ALD) thin film coating technology. ALD-GCA-MCPs are a technology advancement that affords MCPs with significantly improved performance, as compared to the conventional MCP manufacturing process. Notable advancements over conventional lead-oxide based MCPs are larger size, high and stable gain, low dark counts and gamma-ray insensitivity, improved mechanical stability, and the unique ability to tune the MCP resistance and electron amplification characteristics over a much wider range. MCPs find application in a variety of photon counting applications and are particularly suited for charged particle detection that requires high timing and spatial resolution, such as Ion-TOF, electron spectroscopies, analytical and space instruments. Further, Incom is also developing and commercializing the “Large Area Picosecond Photo Detector” (LAPPDTM), the world largest MCP-based photodetector featuring a sensitive area of up to 350 cm2, single photoelectron sensitivity at a gain exceeding 107, high timing resolution of about 50pS and sub-mm spatial resolution. LAPPD has a compact flat-panel sealed glass envelope that contains a highly sensitive bi-alkali photocathode with a quantum efficiency (QE) of up to 30%. Photoelectrons are amplified by a chevron pair of ALD-GCA-MCPs. The amplified signals are collected on microstrip anodes applied to the bottom plates which exit the detector via pin-free hermetic seals under the side walls. We report performance results achieved for fully functional sealed LAPPDs™. The detector achieves electron gains of up to 107, low dark noise rates (15-30 Cts/s/cm2), single photoelectron (PE) timing resolution of 64 picoseconds RMS (with 25pS FWHM laser pulses), and single photoelectron spatial resolution along and across strips of 1.3mm and 0.8 mm RMS respectively. While not fully optimized, LAPPD have been qualified in early adopter applications. LAPPDs will find application in neutrino experiments (e.g. ANNIE, WATCHMAN, DUNE), particle collider experiments (e.g. EIC), neutrinoless double-beta decay experiments (e.g. NuDoT) and other relevant applications, such as PET imaging, florescence spectroscopy, . We provide an overview of Incom’s MCP and LAPPD sensor technologies and report on the recent progress in pilot manufacturing of ALD-GCA-MCPs and LAPPDs. We will also discuss future prospects of the latest developments in ALD-GCA-MCPs and LAPPDs.