arXiv subjects

Austin de St Croix

Publications and source records attributed to Austin de St Croix.

3 recordsLinked to original sources

arXiv2026

Performance of FBK VUV-HD3 and HPK VUV4 SiPMs in the Light-only Liquid Xenon (LoLX) Detector

Silicon Photomultipliers (SiPMs) are a critical technology for the next generation of rare-event search experiments using liquid xenon (LXe). LXe scintillation is emitted primarily in the vacuum-ultraviolet (VUV), requiring photosensors with high VUV detection efficiency under cryogenic operating conditions. Direct characterization of VUV-sensitive SiPMs in LXe is therefore important for informing detector design and comparing device response. This work presents a direct comparison of Fondazione Bruno Kessler (FBK) VUV-HD3 and Hamamatsu (HPK) VUV4 SiPMs operated simultaneously within the Light-only Liquid Xenon (LoLX) detector. Using data collected with gamma sources placed outside the detector, we characterized the relative performance of these photosensors. Our analysis reveals that under these operating conditions, the HPK SiPMs observe 33-38% less light than the FBK devices, a larger difference than predicted by standard PDE models in vacuum measurements. We show that this discrepancy is resolved by an angular and wavelength dependent PDE model incorporating surface shadowing effects into our optical simulation, which then accurately reproduces the experimental data. This finding has significant implications for the selection and implementation of photosensors in future large-scale LXe detectors.

physics.ins-det↗

arXiv2026

Demonstrating a broadband Photon Detection Efficiency model on VUV sensitive Silicon Photomultipliers

We present a versatile analytic model describing Photon Detection Efficiency (PDE) for P-on-N silicon photomultipliers, with possible applications for device characterization, PDE extrapolation from limited data, simulation and design optimization. Using device specific parameters, SiPM PDE is modeled as a function of wavelength, angle of incidence, voltage, and limited temperature range. By factoring the PDE into transmission and internal efficiency, the performance in liquid nobles and other dense media can be predicted. We present the measurement of the absolute PDE from 350 to 830 nm at 163 K for two VUV sensitive SiPMs: a Hamamatsu VUV4 and Fondazione Bruno Kessler VUV-HD Technology. Additional measurements of relative PDE versus angle are also included. We successfully fit the model to the data, compare with literature and show the model's predictive power by extrapolating PDE to new wavelengths and operation in liquid xenon and argon, which is useful for estimating performance and the impact of external cross-talk in future large-scale experiments. Lastly we use the model to investigate optimizing efficiency for specific applications in astroparticle physics and quantum computing.

physics.ins-det↗

arXiv2024

Stimulated Secondary Emission of Single Photon Avalanche Diodes

Large-area next-generation physics experiments rely on using Silicon Photo-Multiplier (SiPM) devices to detect single photons, which trigger charge avalanches. The noise mechanism of external cross-talk occurs when secondary photons produced during a charge avalanche escape from an SiPM and trigger other devices within a detector system. This work presents measured spectra of the secondary photons emitted from the Hamamatsu VUV4 and Fondazione Bruno Kessler VUV-HD3 SiPMs stimulated by laser light, near operational voltages. The work describes the Microscope for the Injection and Emission of Light (MIEL) setup, which is an experimental apparatus constructed for this purpose. Measurements have been performed at a range of over-voltage values and temperatures from 86~K to 293~K. The number of photons produced per avalanche at the source are calculated from the measured spectra and determined to be 40$\pm$9 and 61$\pm$11 photons produced per avalanche for the VUV4 and VUV-HD3 respectively at 4 volts over-voltage. No significant temperature dependence is observed within the measurement uncertainties. The overall number of photons emitted per avalanche from each SiPM device are also reported.

physics.ins-det↗