Development of a novel, windowless, amorphous selenium based photodetector for use in liquid noble detectors

Abstract

A: Detection of the vacuum ultraviolet (VUV) scintillation light produced by liquid noble elements is a central challenge in order to fully exploit the available timing, topological, and calorimetric information in detectors leveraging these media. In this paper, we characterize a novel, windowless amorphous selenium based photodetector with direct sensitivity to VUV light. We present here the manufacturing and experimental setup used to operate this detector at low transport electric fields (2.7-5.2 V/𝜇m) and across a wide range of temperatures (77K-290K). This work shows that the first proof-of-principle device windowless amorphous selenium is robust under cryogenic conditions, responsive to VUV light at cryogenic temperatures, and preserves argon purity. These findings motivate a continued exploration of amorphous selenium devices for simultaneous detection of scintillation light and ionization charge in noble element detectors.

Physics Opportunities in the ORNL Spallation Neutron Source Second Target Station Era

“…The opaque pixelated charge collection system makes it impossible to keep the conventional TPC design, in which the light detectors are mounted behind the wire-based charge readout planes. A few R&D projects are currently progressing, pursuing a few percent of light detection efficiency and a few nanoseconds of time resolution [63][64][65][66].…”