Behaviour of large-area avalanche photodiodes under intense magnetic fields for VUV- visible- and X-ray photon detection

Abstract

The behaviour of large-area avalanche photodiodes for X-rays, visible and vacuum-ultra-violet (VUV) light detection in magnetic fields up to 5 T is described. For X-rays and visible light detection, the photodiode pulse amplitude and energy resolution were unaffected from 0 to 5 T, demonstrating the insensitivity of this type of detector to strong magnetic fields. For VUV light detection, however, the photodiode relative pulse amplitude decreases with increasing magnetic field intensity reaching a reduction of about 24% at 5 T, and the energy resolution degrades noticeably with increasing magnetic field. r

Detection of VUV Light with Avalanche Photodiodes

“…Different studies have proven the APD response characteristics for VUV light to be different from those for visible light, which has been originally used to determine most of the characteristics of photodiodes [20][21][22][23]. This is due to the difference in the average interaction depth of the photons, which is approximately 1 μm for 520-nm photons and approximately 5 nm for 172-nm photons [29].…”

“…The insensitivity of the APD response to magnetic fields in X-ray and visible-light detection is well documented [23,25,42]. In opposition to visible light and X-ray detection, where the APD response is insensitive to magnetic fields, VUV detection with APDs is sensitive to magnetic fields.…”

“…For the 128 and 172 nm VUV light from argon and xenon scintillation, the effective quantum efficiency, here defined as the average number of free electrons produced in the APD per incident VUV photon is 0.5 and 1.1, respectively, corresponding to a spectral sensitivity of about 50 and 150 mA/W [4,19]. In this chapter, we review and summarize the results of our investigation, namely the gain non-linearity between the detection of X-rays and VUV light [20], the gain dependence on temperature [21,22], the behaviour under intense magnetic fields [23], the minimum detection limit, i.e. the minimum number of photons detectable above the noise level, and the statistical fluctuations in VUV photon detection [24].…”

Detection of VUV photons with large-area avalanche photodiodes

“…Different studies have proved that the LAAPD response characteristics for VUV are different from those for visible light, used to determine most of the characteristics of the photodiodes [20][21][22]. The X-ray-to-photon detection nonlinearity, the sensitivity to magnetic fields and the relative variation of gain with temperature have been measured for VUV, presenting higher values when compared to visiblelight detection.…”

“…These LAAPDs can replace PMTs or CsI-based photosensors in applications where the light level allows the use of low-gain photosensors [11,12,[16][17][18][19]. For example, the detection of primary and secondary scintillation in rare gases is not only used in gas scintillation X-ray detectors [11,12], but also in many other types of radiation detectors, which have been investigated recently [16][17][18][19].Different studies have proved that the LAAPD response characteristics for VUV are different from those for visible light, used to determine most of the characteristics of the photodiodes [20][21][22]. The X-ray-to-photon detection nonlinearity, the sensitivity to magnetic fields and the relative variation of gain with temperature have been measured for VUV, presenting higher values when compared to visiblelight detection.…”