Michael Minot, Incom Inc., Bernhard W. Adams, Incom Inc., Melvin Aviles, Incom Inc, Justin L. Bond, Incom Inc, Christopher A. Craven, Incom Inc., Till Cremer, Incom Inc., Michael R. Foley, Incom Inc., Alexey Lyashenko, Incom Inc., Mark A. Popecki, Incom Inc., Michael E. Stochaj, Incom Inc., William A. Worstell, Incom Inc., Jeffrey W. Elam, Argonne National Laboratory, Anil U. Mane, Argonne National Laboratory, Oswald H. W. Siegmund, University of California, Berkeley, Camden Ertley, University of California, Berkeley.
Keywords: Microchannel plate, photon counting, imaging, timing, large area photodetector, ALD MCP
Abstract:
Pilot production performance is reported for large area atomic layer deposition (ALD) coated microchannel plates (ALD-GCA-MCPs) and for Large Area Picosecond Photodetectors (LAPPD™) which incorporate them. “Hollowcore†glass capillary array (GCA) substrates are coated with ALD resistive and emissive layers to form the ALDGCA- MCPs, an approach that facilitates independent selection of glass substrates that are mechanically stronger and that have lower levels of radioactive alkali elements compared to conventional MCP lead glass, reducing background noise[1,2,3,4]. ALD-GCA-MCPs have competitive gain (~104 each or ~107 for a chevron pair ), enhanced lifetime and gain stability (7 C cm-2 of charge extraction), reduced background levels (0.028 events cm-2 sec-1) and low gamma-ray detection efficiency. They can be fabricated in large area (20cm X 20 cm) planar and curved formats suitable for use in high radiation environment applications, including astronomy, space instrumentation, and remote night time sensing. The LAPPD™ photodetector incorporates these ALD-GCA-MCPs in 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, amplified with a stacked chevron pair of ALD-GCA-MCPs. Signals are collected on RF strip-line anodes integrated into to the bottom plates which exit the detector via pin-free hermetic seals under the side walls [5]. Tests show that LAPPDTMs have electron gains greater than 107, submillimeter spatial resolution for large (multiphoton) pulses and several mm for single photons, time resolution less than 50 picoseconds for single photons, predicted resolution less than 5 picoseconds for large pulses, high stability versus charge extraction[6], and good uniformity for applications including astrophysics, neutron detection, high energy physics Cherenkov light detection, and quantum-optical photon-correlation experiments.
Date of Conference: September 20-23, 2016
Track: Poster