Performance degradation of Geiger-mode APDs at cryogenic temperatures

Abstract

Two-phase Cryogenic Avalanche Detectors (CRADs) with THGEM multipliers, optically read out with Geiger-mode APDs (GAPDs), were proposed as potential technique for charge recording in rare-event experiments. In this work we report on the degradation of the GAPD performance at cryogenic temperatures revealed in the course of the study of two-phase CRAD in Ar, with combined THGEM/GAPD-matrix multiplier; the GAPDs recorded secondary scintillation photons from the THGEM holes in the Near Infrared. The degradation effect, namely the loss of the GAPD pulse amplitude, depended on the incident X-ray photon flux. The critical counting rate of photoelectrons produced at the 4.4 mm 2 GAPD, degrading its performance at 87 K, was estimated as ~10 4 s -1 . This effect was shown to result from the considerable increase of the pixel quenching resistor of this CPTA-made GAPD type. Though not affecting low-rate rare-event experiments, the observed effect may impose some limitations on the performance of CRADs with GAPD-based optical readout at higher-rate applications.

First demonstration of THGEM/GAPD-matrix optical readout in a two-phase Cryogenic Avalanche Detector in Ar

“…In this case, some pulses were even lost below threshold, thus reducing the PDE of the GAPD. This GAPD rate-dependence problem was studied elsewhere [11]: it is shown to be due to a considerable increase of the pixel quenching resistor at low temperatures, observed earlier for this particular GAPD type [7].…”

MPPC versus MRS APD in two-phase Cryogenic Avalanche Detectors

“…Note that the contribution of the after-pulses at the maximum voltage was inessential, below 15%. Recently the effect of the GAPD performance degradation at cryogenic temperatures, at higher incident photon fluxes, has been observed for GAPDs of the MRS APD type [16]. The critical counting rate of photoelectrons produced at MRS APD 149-35 to degrade its performance at 87 K, was estimated to be of the order of 10 4 s -1 .…”

“…The details of the experimental procedures regarding determination of the GAPD noise rate, gain and pixel resistance, can be found elsewhere [7], [16], [23]. In particular, the noise rate was measured by counting the noise pulses in a given time interval, the noise signals being recognized by their characteristic pulse-shapes.…”

“…Accordingly, it is important to make a proper choice of the GAPD sensor, which should have a higher efficiency in the NIR, higher gain, lower noise rate and higher performance reliability at cryogenic temperatures. In addition it is desirable to have a lower GAPD pixel quenching resistor, to prevent the effect of the GAPD performance degradation at cryogenic temperatures observed elsewhere [16]. It should be remarked that though the GAPD operation at cryogenic temperatures was repeatedly studied [17][18][19][20][21][22][23][24][25], the understanding of their performance at low temperatures is still incomplete.…”

Study of combined THGEM/GAPD-matrix multiplier in a two-phase Cryogenic Avalanche Detector in Ar

“…2 one can see that the signals from the GAPD have rather different pulse-heights, with the tendency to smaller values. This is due to the effect of the GAPD performance degradation at lower temperatures observed recently [16,17]. This effect manifested itself at higher photon fluxes; it resulted from the increase of the GAPD pixel recovery time due to the increase of the pixel quenching resistor at cryogenic temperatures.…”