Performance of Hamamatsu R11410-20 PMTs under intense illumination in a two-phase cryogenic emission detector

Abstract

Hamamatsu R11410-20 PMTs are used in the RED-100 two-phase xenon emission detector built to search for the rare process of coherent elastic neutrino-nucleus scattering using intense artificial neutrino flux. We demonstrate how to adapt the PMTs for their operation under strong illumination caused by electroluminescent signals from gamma and cosmogenic muon backgrounds which are significant at shallow depth experimental sites. The PMT linearity is demonstrated for signals in the dynamic range from 1 to 2*10 4 photoelectrons. Impact of a photoelectric effect at the PMT first dynode to the capabilities of the RED-100 photodetection system is studied and quantified. K: Neutrino detectors; Noble liquid detectors (scintillation, ionization, double-phase); Photon detectors for UV, visible and IR photons (vacuum) 1Corresponding author.

First ground-level laboratory test of the two-phase xenon emission detector RED-100

“…The two-phase emission detector RED-100 (figure 2) contains ∼ 200 kg of liquid xenon (total amount) and ∼ 160 kg in a Teflon-made light collection dodecagon prism placed inside an electrode drift system. The liquid xenon TPC is viewed by two arrays of 19 Hamamatsu R11410-20 PMTs [26][27][28] and is installed into a titanium cryostat [29]. Detailed description of the RED-100 detector is given in [19].…”

“…The electron shutter also serves to satisfy the 1-st requirement: the illumination of PMTs by electroluminescence from muons is significantly reduced, because only the above-G2 part of the muon track produces the light. To avoid detection of this part of the light by PMTs, our previously developed method of PMT disabling by applying a positive pulsed bias (the same 300-V pulse) to photocathodes is used (see details in [26,28]).…”

Computer modelling of the Hamamatsu R11410-20 PMT

“…The PMT bases are directly connected to the photomultiplier pins. The specific of the RED-100 detector operation requires the very wide dynamic range of PMT: from the single photoelectron signals of small scintillation to the very intense electroluminescent signals having several millions of photoelectrons; see for details [3] paper. Moreover, the rate of appearance of scintillation signal is substantially high, and the significant average anode current may result in nonlinearity of the PMT gain.…”