The fields of astro-particle physics, nuclear medical imaging and nuclear security—which all rely on large-area photosensors—have been virtually stuck with the expensive 80-year old photomultiplier tube (PMT) fabrication and manufacturing process. The peculiar combination of construction materials, which is incompatible with modern mass-production technologies, necessitates a very slow, labor-intensive and expensive vacuum process. All attempts to invent a modern replacement for the labor-intensive PMT manufacture have so far failed. Concepts like Smart-PMTs, Quasar, Hybrid Photo-Diodes, and PMTs with microchannel plates have all failed to provide an inexpensive mass-production method because they have relied on the very same combination, or even more problematic sets of construction materials. Therefore, the search for a truly modern mass-production technology started with a fundamentally new definition of allowed processes and construction materials. The goal was achieved with the invention of the ABALONE Photosensor concept [Patent US9064678], comprising of three vacuum-processed components that are all mass-producible out of glass. Strictly excluded components from consideration are: any metals, silicon photodiodes, microchannel plates and ceramics. The only processing method employed is the common thin-film vacuum coating technique, equivalent to the production of compact discs (CDs).

This new production technology has been fully implemented and thoroughly proven in long-term prototype tests. This thesis reports on part of the continuous, three-year long test of an ABALONE Photosensor prototype, manufactured in May of 2013 in the custom-designed ABALONE Photosensor Pilot Production Plant (A4P), in the Ferenc-Lab at UC Davis. The most important results from these studies have been the vacuum integrity, the unprecedentedly high vacuum cleanliness, the fast time resolution and the unique single-photon resolution of the ABALONE Photosensor prototype. The results reported here focus specifically on the single-photon sensitivity, and the single- and multiple-photon resolution. In addition, we will discuss the dynamic range of the ABALONE Photosensor.