Air-transfer production method for large-area picosecond photodetectors.

We have designed and prototyped the process steps for the batch production of large-area micro-channel-plate photomultipliers (MCP-PMT) using the "air-transfer" assembly process developed with single LAPPD modules. Results are presented addressing the challenges of designing a robust package that can transmit large numbers of electrical signals for pad or strip readout from inside the vacuum tube and of hermetically sealing the large-perimeter window-body interface. We have also synthesized a photocathode in a large-area low-aspect-ratio volume and have shown that the micro-channel plates recover their functionality after cathode synthesis. These steps inform a design for a multi-module batch facility employing dual nested low-vacuum and ultra-high-vacuum systems in a small-footprint. The facility design provides full access to multiple MCP-PMT modules prior to hermetic pinch-off for leak-checking and real-time photocathode optimization.