Resistive coatings for high-performance, low-background MCPs operating across broad temperature ranges and at cryogenic temperatures

The planned “Deep Underground Neutrino Experiment” (DUNE), will become the premier High Energy Physics (HEP) Neutrino Physics research facility in the world, and will be constructed over the coming decade. DUNE and its associated short-baseline surface neutrino detectors will be enormous Liquid Argon T ime Projection Chambers, recording tracks from neutrino interaction secondary particles in exquisite detail by drifting patterns of ionization charge through giant vats of ultrapure cryogenic noble liquid. Photon detection systems will play a crucial role in DUNE and its associated neutrino experiments, but requirements for the cost-effective large-area photosensors needed to collect very hard VUV light in Liquid Argon environment are very demanding. Over the last decade we have developed a room-temperature baseline Large Area Picosecond Photon Detectors (LAPPDTM), a 203 mm x 203 mm flat photosensor with unsurpassed photon timing accuracy. The core element of this detector is Incom’s next generation microchannel plate (MCP) technology, which was also developed within the DOE-supported LAPPD consortium. Herein, we propose to develop a new generation of MCPs with improved thermo-electrical properties, specifically addressing undesired resistance changes with temperature. The resulting MCPs will have superior voltage and gain stability, be less prone to thermal runaway, and can be further optimized to operate reliably at cryogenic temperatures. Other applications such as space science instrumentation, field-deployed radiation detectors for homeland security applications as well as industrial high and low-temperature applications such as the mining or oil prospecting industry are expected to benefit from this development. In Phase I, working closely with Argonne National Laboratory and University of California, Berkeley – Space Science Laboratories, we propose proof-of-concept demonstration of resistive coatings that exhibit an extremely low, or negligible temperature coefficient of resistance. In Phase II we will apply these coatings to fabricate MCPs that exhibit stable gain and resistance over wide temperature ranges, and that can be optimized to reliably operate at cryogenic or elevated temperatures. This innovation will enable new detector plications in HEP, nuclear physics, spectroscopy, and calorimetry applications, as well as in medical imaging, homeland security, and energy sectors. Key words: LAPPDTM, High Energy Physics, cryogenic particle detector, thermal runaway, atomic layer deposition, temperature coefficient of resistance, TCR, microchannel plates, MCP.