LEGEND is searching for neutrinoless double-beta (0νββ) decay of ⁷⁶Ge using isotopically enriched high-purity germanium detectors operated bare in liquid argon (LAr), which serves as coolant, shielding, and active detector. Achieving and maintaining excellent LAr purity is essential, as oxygen, water, and nitrogen impurities degrade scintillation and optical properties and thus deteriorate...
Efficient detection of vacuum-ultraviolet scintillation light remains a central challenge for liquid noble detectors, particularly as future experiments move toward highly segmented, pixelated readout architectures. Amorphous selenium (a-Se) offers an appealing path toward scalable, cryogenic photon detection because it combines low dark current, thin-film manufacturability, broad spectral...
Detecting low-energy xenon recoils from dark matter or neutrino interactions requires a nuanced understanding of near-threshold signal yields in liquid xenon. This necessitates specialized neutron calibration. In this presentation, I will discuss recent measurements of scintillation and ionization yields in liquid xenon in the LUX-ZEPLIN (LZ) detector using a deuterium-deuterium neutron...
The next generation of liquid argon time projection chambers, such as those employed in the Deep Underground Neutrino Experiment (DUNE), requires ultra-high purity liquid argon to ensure long electron lifetimes and optimal detector performance. Oxygen is one of the most critical electronegative contaminants, and its efficient removal during cryostat filling is essential to reduce detector...
The Deep Underground Neutrino Experiment (DUNE) will employ liquid argon time projection chambers (LArTPCs) at unprecedented scales for its far detectors and under unprecedented neutrino beam intensities in its near detector. To meet their performance requirements for ionization electron readout, these LArTPCs require custom electronics capable of operating in cryogenic conditions. This has...
DarkSide-20k, currently under construction at LNGS, is a next-generation dual-phase liquid argon Time Projection Chamber designed for the direct search of WIMP dark matter. Within the DarkSide-20k program, Proto-0 is a dedicated prototype developed to validate key detector technologies, study signal formation, and support the development and commissioning of detector subsystems for the final...
The Deep Underground Neutrino Experiment (DUNE) Near Detector will be exposed to an extremely intense neutrino flux (over 100 beam-related interactions per spill). To cope with the very high event pile-up, the Near Detector uses a modular array of Liquid Argon time projection chambers (ND-LAr), which incorporates several innovations. Most importantly, a pixelated charge readout system with...
The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment designed to investigate neutrino oscillations, determine the neutrino mass ordering, and search for possible CP violation in the lepton sector. The experiment comprises a Near Detector and a Far Detector located 1300 km apart. The Far Detector will consist of four liquid argon time projection chambers...
Liquid noble gas detectors for neutrino and rare-event searches rely on efficient detection of vacuum-ultraviolet (VUV) scintillation light while minimizing radioactive backgrounds from nearby materials. To improve the detection of VUV photons, wavelength shifters are required to convert scintillation light into the visible range. At the scale of next-generation experiments such as DUNE,...
The Short-Baseline Near Detector (SBND) is a liquid-argon time-projection chamber (LArTPC) for detecting neutrinos from Fermilab's Booster Neutrino Beam. Located 110 m downstream of the beam target, SBND collects both ionization electrons and scintillation photons from particle interactions within the detector volume. With an active mass of 112 tons, it enables high-precision studies of...
The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment designed to perform high-precision measurements of neutrino oscillation parameters, investigate leptonic CP violation, determine the neutrino mass ordering, detect neutrinos from core-collapse supernovae, and search for physics beyond the Standard Model. Its far detector modules will be based on liquid...
Efficient detection of vacuum ultraviolet (VUV) scintillation light is essential to fully exploit the physics potential of next-generation neutrino and dark matter experiments. We are pursuing a broad R&D programme aimed at improving VUV photodetection through innovations in both sensor materials and readout architectures. On the sensor side, we investigate novel concepts including amorphous...
Gaseous wavelength shifting in CF₄-based mixtures: from microscopic modelling to scintillation observables
Gaseous wavelength shifting (GWS) plays a key role in the optical readout of modern micropattern gaseous detectors (MPGDs). It is closely analogous to Penning transfer, but involves excitation transfer rather than ionization transfer. In principle, GWS enables trace additive...
Prolonged exposure of p-terphenyl (PTP) to environmental factors such as light, temperature, and humidity can induce aging processes that degrade their optical performance, potentially compromising the long-term stability and reliability of detector systems. A systematic investigation of these degradation mechanisms is therefore essential for qualifying WLS coatings in experiments, such as...
Next-generation liquid xenon (LXe) time projection chambers (TPCs) aim to push direct dark matter searches to the neutrino fog and support a broader rare-event physics program, including neutrinoless double-beta decay.
Building on these advancements, the next-generation XLZD observatory would scale this technology to an LXe-TPC with a height and inner diameter of nearly $3\,\mathrm{m}$,...
Silicon Photomultipliers (SiPMs) are compact, high gain photon detectors widely used in particle physics and medical imaging. In conventional front side–illuminated (FSI) devices, light enters through the same surface that hosts metal routings and quenching resistors, limiting the fill factor and the photon detection efficiency. By adopting a backside illuminated (BSI) architecture, photons...
It is known that for noble liquids, experimental data on the Fano factor for nuclear recoils remain sparse; consequently, many experiments fix this factor to unity, assuming binomial statistics. In this work, we present a formal theory, based on the Lindhard integral equation, to compute the statistical variance arising from nuclear recoil energy depositions. The model is based on the solution...
Wavelength shifters (WLS) are widely employed in high-energy physics experiments to con-vert ultraviolet (UV) and vacuum ultraviolet (VUV) radiation into wavelengths compatible with the spectral sensitivity of photodetectors. Among the materials investigated in this work are p-terphenyl (PTP), tetraphenyl butadiene (TPB), and polyethylene naphthalate (PEN), which are commonly used in...
The LEGEND experiment is designed to search for neutrinoless double beta decay of Ge-76. This decay, if observed, would establish the Majorana nature of neutrinos and demonstrate lepton number non-conservation. The first stage of the program, LEGEND-200, is currently taking physics data at the INFN Laboratori Nazionali del Gran Sasso and can accommodate up to about 200 kg of enriched...
The LUX-ZEPLIN experiment is a liquid-gas dual phase time projection chamber that utilizes 7 active tonnes of liquid xenon as a target for dark matter searches and observatory for neutrino-less double beta and other rare nuclear processes. It has been collecting science data near-continuously since 2021. In this time we have published the world leading limits on WIMP dark matter, reported the...
The NEXT experiment aims to detect neutrinoless double-beta decay using a high-pressure xenon gas time projection chamber with electroluminescence. To successfully reject background, the detector relies on excellent energy resolution and high-performance tracking capabilities.
Scaling traditional photomultiplier tube (PMT) technology for the future ton-scale phase of the experiment presents...
Neon is a light element, making it well-suited for the detection of low-energy nuclear recoils from dark matter and neutrinos. In particular, reactor antineutrinos are difficult to detect via coherent elastic neutrino-nucleus scattering (CE$\nu$NS) due to the characteristically low-energy recoils they produce. The COHERENT Collaboration is planning to redeploy the CENNS-10 detector hardware as...
Efficient detection of 178 nm VUV scintillation light is a staple of xenon-based detectors for rare-event searches, including next-generation experiments to search for neutrinoless double beta (0νββ) decay like nEXO. nEXO is a 5-tonne liquid xenon (LXe) time-projection chamber enriched to 90% Xe-136 designed to search for 0νββ decay with a projected half-life sensitivity of 1.35*10^28 years...
Scintillation light is a powerful tool in liquid argon (LAr) based detectors for rare events searches, since it can be used for timing, calorimetric and particle discrimination purposes. Photons are emitted in the Vacuum Ultra Violet, in a ten nm band centered around 128 nm where most of the commercially available photosensors are not sensitive. p-Terphenyl (PTP) thin films are a common...
Ultrapure liquid Argon (LAr) is a heavily used target for neutrino detection. Recently, an innovative adsorbent R-LDH based on layered double hydroxides has shown higher performance for oxygen capture in liquid argon than other materials frequently used [1]. This work aimed to develop a new pelletization methodology for the R-LDH materials containing highly dispersed CuO that can allow the...
Dual-phase argon Time Projection Chambers (TPCs) are a leading technology for rare-event searches including dark matter WIMP and neutrino interactions. Searching for dark matter candidates at lower masses requires detectors with lower energy thresholds than those of current noble liquid TPCs. Our research focuses on optimizing detector materials for very low energy deposition events, such as...
Liquid Argon Time Projection Chambers (LArTPCs) rely on large-area photon detectors to detect liquid argon scintillation light necessary for precise event timing, triggering and complementary calorimetry alongside the charge readout.
Liquid argon emits scintillation light predominantly at 128 nm in the vacuum ultraviolet (VUV) region. As this wavelength cannot be efficiently detected by...
The MainzTPC is a dual-phase xenon time projection chamber (TPC) containing roughly 300 g of liquid xenon (LXe) and is dedicated to the study of scintillation and ionization processes in LXe for low-energy electronic and nuclear recoils. It has been designed to be the primary target in Compton and neutron scattering experiments to measure recoil energies in LXe down to 1 keV. To improve...
AI has had a transformative effect on particle physics, including visual pattern recognition in liquid argon time-projection chamber (LArTPC) experiments. To solve complex topological problems both at trigger level and in offline reconstruction, algorithms are currently deployed on CPUs or GPUs. The former are unspecialised chips with low speed, whilst the latter offer high speed but at the...
The DarkSide-20k is a next-generation dark matter experiment aiming at a direct detection of Weakly Interacting Massive Particles (WIMPs) via nuclear recoils in liquid argon. The detector, currently under construction at the Gran Sasso National Laboratory (LNGS), Italy, will benefit from the natural shielding against cosmic rays provided by the lab’s underground location. It will employ a...
The RELICS (REactor neutrino LIquid xenon Coherent elastic Scattering) experiment employs a dual-phase liquid xenon time projection chamber to search for Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) induced by reactor neutrinos. To detect these sub-keV nuclear recoils and minimize signal attenuation, it is critical to maintain a sufficiently low impurity concentration in the...
A proof-of-concept test of the PoWER (Polymer Wavelength Shifter and Enhanced Reflection) photon detection system was carried out at the Leptons Laboratory of UNICAMP. PoWER is an innovative photon detection concept for large liquid argon (LAr) detectors, designed to achieve an exceptionally high light yield—potentially reaching several hundred photoelectrons per MeV—while providing an active...
The Dark matter Experiment using Argon Pulseshape discrimination (DEAP-3600) is a leading single-phase liquid argon experiment located 2 km underground at SNOLAB. The experiment was designed and optimized for sensitivity to nuclear recoils produced by WIMP dark matter through careful material screening, immense overburden, passive shielding, and careful analysis methods. Many of these...
The Scintillating Bubble Chamber (SBC) collaboration is developing liquid noble bubble chambers as a technology for the detection of low energy (sub-keV) nuclear recoils. Identifying recoils at this energy would enable searches for light dark matter (~GeV mass), as well as the observation of coherent elastic neutrino nucleus scattering (CEvNS) at low neutrino energy (~MeV, such as from a...
PandaX (Particle and Astrophysical Xenon experiment), a large-scale liquid xenon dark matter detection project located at the China Jinping Underground Laboratory, has provided a high-sensitivity experimental platform for dark matter and neutrino searches through the iterative development of three generations of detectors since its launch in 2009. As a core leading institution of the...
Doping liquid argon (LAr) with a few parts per million (ppm) mass of xenon (Xe) is a known technique to modify the scintillation light properties. The energy deposited by charged particles crossing the detector is transferred from argon excimers to xenon excimers, through the process Ar2->ArXe->Xe2*, which emits photons with a longer wavelength. These effects are expected to affect the light...
LEGENDArYno is a newly constructed liquid argon (LAr) R&D setup located at LNGS. Its primary purpose is to provide suitable, realistic conditions for testing prototype Light Detection Modules (LDMs) envisioned for the Outer LAr volume instrumentation of the future LEGEND-1000 detector. The experimental setup is housed in a 140-cm-tall, 40-cm-diameter cryostat equipped with liquid nitrogen...
Thanks to its excellent properties, xenon is widely used as a target material in dark matter and rare-event search experiments. Ultraviolet scintillation has long been recognized as the primary signal channel in xenon-based detectors and its properties have been well studied. However, xenon also scintillates infrared light, a component which has received very little attention so far. Taking...
The Short-Baseline Near Detector (SBND) is a liquid-argon time-projection chamber (LArTPC) for detecting neutrinos from Fermilab's Booster Neutrino Beam. Located 110 m downstream of the beam target, SBND collects both ionization electrons and scintillation photons from particle interactions within the detector volume. The photon detection system (PDS) consists of both PMTs and X-ARAPUCAs, with...
Currently under construction in the United States, the Deep Underground Neutrino Experiment (DUNE) is a next-generation international experiment focused on neutrino oscillation studies. The DUNE Far Detector will consist of four 17-kton Liquid Argon Time Projection Chamber (LArTPC) modules, two with established geometries and technologies in Phase I, while the remaining two are under...
The Deep Underground Neutrino Experiment (DUNE) employs large Liquid Argon Time Projection Chambers (LArTPCs) to address key questions in neutrino physics and astroparticle physics. Doping Liquid Argon (LAr) with xenon is proposed to improve light-collection uniformity and efficiency, thereby improving timing, triggering, and low-energy physics capabilities. This work details xenon-doping...
