arXiv subjects

A. Breskin

Publications and source records attributed to A. Breskin.

At least 19 recordsLinked to original sources

arXiv2026

Development of a Multi-Purpose Optical TPC for Neutron-Induced Reaction Studies at SARAF

Neutron-induced reactions play a central role in stellar and Big Bang nucleosynthesis models. Yet many of the cross sections remain poorly constrained at astrophysically relevant energies. To address these needs, we are developing a multi-purpose Optical Time Projection Chamber (OTPC) optimized for precision neutron-reaction studies at the Soreq Applied Research Accelerator Facility (SARAF) upcoming high-intensity, time-of-flight neutron beam. The detector combines a drift chamber filled with CF4-based scintillating gas mixtures, fast photodetectors for prompt scintillation detection, and high-speed optical readout of avalanche-induced secondary scintillation to enable full 3D reconstruction of charged-particle tracks. A prototype system has been assembled and tested. This has enabled systematic characterization of electron drift velocity, charge and light amplification, and 2D optical imaging of alpha-particle tracks in an Ar/CF4 gas mixture. These studies guide the design of a larger, fully integrated OTPC system intended for operation at SARAF. In parallel, we are exploring advanced image sensors to further enhance tracking resolution. We report on recent progress with the prototype and outline the next steps toward commissioning the full system.

physics.ins-det↗

arXiv2026

Advances in photocathode development for PICOSEC Micromegas precise-timing detectors

The PICOSEC Micromegas detector is a~precise-timing gaseous detector that combines a Cherenkov radiator, a~semi-transparent photocathode and a Micromegas amplification stage, targeting time resolutions of tens of picoseconds for minimum ionising particles (MIPs). Initial single-pad prototypes achieved time resolutions of $\sigma<25$ ps, demonstrating strong potential for High Energy Physics (HEP) applications and beyond. The objective of this paper is a comprehensive characterisation of photocathodes, with a strong focus on robust materials while preserving excellent timing performance. The study includes laboratory measurements of optical and resistive properties, along with beam tests using 150 GeV/$c$ muons to evaluate the time resolution and photoelectron yield for various photocathodes. The best performance was obtained by a 5 nm Cesium Iodide (CsI) photocathode, reaching $\sigma = 10.9 \pm 0.3$ ps with more than 30 extracted photoelectrons, representing the most precise time resolution achieved by PICOSEC Micromegas to date. Metallic and carbon-based photocathodes, including Titanium (Ti), Boron Carbide (B$_4$C) and Diamond-Like Carbon (DLC), were also tested, with Ti and B$_4$C emerging as the most promising alternatives, achieving $\sigma \approx 30$ ps with about 5 extracted photoelectrons. These results demonstrate that improved robustness can be achieved while maintaining excellent time resolution, supporting the feasibility of using the PICOSEC Micromegas concept in future experiments.

physics.ins-det↗

arXiv2026

Towards a Reflective PICOSEC detector?

PICOSEC is an ultrafast particle-detector concept, combining a photocathode-coated Cherenkov radiator coupled to a gas-avalanche multiplier. Particle-induced Cherenkov photons create photoelectrons emitted from an ultrathin semitransparent photocathode; they are multiplied and detected in fast gas-avalanche mode. In parallel to the constant progress made in the PICOSEC technique, we propose different detector configurations and operation modes with the aim of enhancing robustness and performance. They incorporate thick reflective photocathodes deposited on the readout electrodes of various types of avalanche multipliers. Some of these Reflective-PICOSEC detectors operate at mbar gas pressures.

physics.ins-det↗

arXiv2024

Neutrinoless Double Beta Decay Sensitivity of the XLZD Rare Event Observatory

The XLZD collaboration is developing a two-phase xenon time projection chamber with an active mass of 60 to 80 t capable of probing the remaining WIMP-nucleon interaction parameter space down to the so-called neutrino fog. In this work we show that, based on the performance of currently operating detectors using the same technology and a realistic reduction of radioactivity in detector materials, such an experiment will also be able to competitively search for neutrinoless double beta decay in $^{136}$Xe using a natural-abundance xenon target. XLZD can reach a 3$\sigma$ discovery potential half-life of 5.7$\times$10$^{27}$ yr (and a 90% CL exclusion of 1.3$\times$10$^{28}$ yr) with 10 years of data taking, corresponding to a Majorana mass range of 7.3-31.3 meV (4.8-20.5 meV). XLZD will thus exclude the inverted neutrino mass ordering parameter space and will start to probe the normal ordering region for most of the nuclear matrix elements commonly considered by the community.

physics.ins-det↗

arXiv2024

The XLZD Design Book: Towards the Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

This report describes the experimental strategy and technologies for XLZD, the next-generation xenon observatory sensitive to dark matter and neutrino physics. In the baseline design, the detector will have an active liquid xenon target of 60 tonnes, which could be increased to 80 tonnes if the market conditions for xenon are favorable. It is based on the mature liquid xenon time projection chamber technology used in current-generation experiments, LZ and XENONnT. The report discusses the baseline design and opportunities for further optimization of the individual detector components. The experiment envisaged here has the capability to explore parameter space for Weakly Interacting Massive Particle (WIMP) dark matter down to the neutrino fog, with a 3$\sigma$ evidence potential for WIMP-nucleon cross sections as low as $3\times10^{-49}\rm\,cm^2$ (at 40 GeV/c$^2$ WIMP mass). The observatory will also have leading sensitivity to a wide range of alternative dark matter models. It is projected to have a 3$\sigma$ observation potential of neutrinoless double beta decay of $^{136}$Xe at a half-life of up to $5.7\times 10^{27}$ years. Additionally, it is sensitive to astrophysical neutrinos from the sun and galactic supernovae.

hep-ex↗

arXiv2024

Model-independent searches of new physics in DARWIN with a semi-supervised deep learning pipeline

We present a novel deep learning pipeline to perform a model-independent, likelihood-free search for anomalous (i.e., non-background) events in the proposed next generation multi-ton scale liquid Xenon-based direct detection experiment, DARWIN. We train an anomaly detector comprising a variational autoencoder and a classifier on extensive, high-dimensional simulated detector response data and construct a one-dimensional anomaly score optimised to reject the background only hypothesis in the presence of an excess of non-background-like events. We benchmark the procedure with a sensitivity study that determines its power to reject the background-only hypothesis in the presence of an injected WIMP dark matter signal, outperforming the classical, likelihood-based background rejection test. We show that our neural networks learn relevant energy features of the events from low-level, high-dimensional detector outputs, without the need to compress this data into lower-dimensional observables, thus reducing computational effort and information loss. For the future, our approach lays the foundation for an efficient end-to-end pipeline that eliminates the need for many of the corrections and cuts that are traditionally part of the analysis chain, with the potential of achieving higher accuracy and significant reduction of analysis time.

physics.ins-det↗

arXiv2024

First studies on cascaded dual-phase liquid hole-multipliers in xenon

Challenges in scaling up noble-liquid time projection chambers prompted the exploration of new detection concepts. The liquid hole-multiplier (LHM) was introduced as a potential component, enabling the detection of ionization electrons and VUV photons. Prior studies focused on perforated electrodes coated with CsI immersed in the liquid and electroluminescence amplification produced on a bubble trapped underneath. However, the performance was hindered by electron transfer across the liquid-gas interface. Here, we explored a bubble-free variant, placing a CsI-coated Thick Gas Electron Multiplier electrode below the liquid-gas interface to improve the transfer efficiency across it. Results show >5-fold improvement in the S1'/S2 ratio (a proxy for the photon detection efficiency (PDE)) compared to the bubble-assisted LHM. Although the achieved PDE is still below expectation ($\sim$4%), we propose potential improvements to enhance the performance of this detector.

physics.ins-det↗

arXiv2024

First observation of liquid xenon electroluminescence with a Microstrip Plate

We report on the first observation of electroluminescence amplification with a Microstrip Plate immersed in liquid xenon. The electroluminescence of the liquid, induced by alpha-particles, was observed in an intense non-uniform electric field in the vicinity of 8-$μ$m narrow anode strips interlaced with wider cathode ones, deposited on the same side of a glass substrate. The electroluminescence yield in the liquid reached a value of $(35.5 \pm 2.6)$ VUV photons/electron. We propose ways of enhancing this response with more appropriate microstructures towards their potential incorporation as sensing elements in single-phase noble-liquid detectors.

physics.ins-det↗

arXiv2023

Cryogenic RPWELL: a novel charge-readout element for dual-phase argon TPCs

The first operation of a cryogenic Resistive Plate WELL (RPWELL) detector in the saturated vapor of liquid argon is reported. The RPWELL detector was composed of a Thick Gas Electron Multiplier (THGEM) electrode coupled to a metallic anode via Fe$_2$O$_3$/YSZ ceramics (Fe$_2$O$_3$ in weight equal to 75$\%$), with tunable bulk resistivity in the range 10$^{9}$ - 10$^{12}$ $Ω\cdot$cm. The detector was operated at liquid argon temperature in saturated argon vapor (90~K, 1.2~bar) and characterized in terms of its effective charge gain and stability against discharges. Maximum stable gain of G$\approx$17 was obtained, without discharges. In addition, preliminary results from novel 3D-printed thermoplastic plates doped with carbon nanotubes are presented.

physics.ins-det↗

arXiv2023

Electron transfer efficiency in liquid xenon across THGEM holes

Dual-phase liquid-xenon time projection chambers (LXe TPCs) deploying a few tonnes of liquid are presently leading the search for WIMP dark matter. Scaling these detectors to 10-fold larger fiducial masses, while improving their sensitivity to low-mass WIMPs presents difficult challenges in detector design. Several groups are considering a departure from current schemes, towards either single-phase liquid-only TPCs, or dual-phase detectors where the electroluminescence region consists of patterned electrodes. Here, we discuss the possible use of Thick Gaseous Electron Multipliers (THGEMs) coated with a VUV photocathode and immersed in LXe as a building block in such designs. We focus on the transfer efficiencies of ionization electrons and photoelectrons emitted from the photocathode through the electrode holes, and show experimentally that efficiencies approaching 100 % can be achieved with realistic voltage settings. The observed voltage dependence of the transfer efficiencies is consistent with electron transport simulations once diffusion and charging-up effects are included.

physics.ins-det↗

arXiv2023

The cryogenic RWELL: a stable charge multiplier for dual-phase liquid-argon detectors

The operation of a cryogenic Resistive WELL (RWELL) in liquid argon vapor is reported for the first time. It comprises a Thick Gas Electron Multiplier (THGEM) structure coupled to a resistive Diamond-Like Carbon (DLC) anode deposited on an insulating substrate. The multiplier was operated at cryogenic temperature (90~K, 1.2~bar) in saturated argon vapor and characterized in terms of charge gain and electrical stability. A comparative study with standard, non-resistive THGEM (a.k.a LEM) and WELL multipliers, confirmed the RWELL advantages in terms of discharge quenching - thus superior gain and stability.

physics.ins-det↗

arXiv2023

Cosmogenic background simulations for the DARWIN observatory at different underground locations

Xenon dual-phase time projections chambers (TPCs) have proven to be a successful technology in studying physical phenomena that require low-background conditions. With 40t of liquid xenon (LXe) in the TPC baseline design, DARWIN will have a high sensitivity for the detection of particle dark matter, neutrinoless double beta decay ($0νββ$), and axion-like particles (ALPs). Although cosmic muons are a source of background that cannot be entirely eliminated, they may be greatly diminished by placing the detector deep underground. In this study, we used Monte Carlo simulations to model the cosmogenic background expected for the DARWIN observatory at four underground laboratories: Laboratori Nazionali del Gran Sasso (LNGS), Sanford Underground Research Facility (SURF), Laboratoire Souterrain de Modane (LSM) and SNOLAB. We determine the production rates of unstable xenon isotopes and tritium due to muon-included neutron fluxes and muon-induced spallation. These are expected to represent the dominant contributions to cosmogenic backgrounds and thus the most relevant for site selection.

physics.ins-det↗

arXiv2023

Novel resistive charge-multipliers for dual-phase LAr-TPCs: towards stable operation at higher gains

Cryogenic versions of Resistive WELL (RWELL) and Resistive Plate WELL (RPWELL) detectors have been developed, aimed at stable avalanche multiplication of ionization electrons in dual-phase TPCs. In the RWELL, a thin resistive layer deposited on top of an insulator is inserted in between the electron multiplier (THGEM) and the readout anode; in the RPWELL, a resistive plate is directly coupled to the THGEM. Radiation-induced ionization electrons in the liquid are extracted into the gaseous phase. They drift into the THGEM's holes where they undergo charge multiplication. Embedding resistive materials into the multiplier proved to enhance operation stability due to the mitigation of electrical discharges - thus allowing operation at higher charge gain compared to standard THGEM (a.k.a. LEM) multipliers. We present the detector concepts and report on the main preliminary results.

physics.ins-det↗

arXiv2023

First results on FHM -- a Floating Hole Multiplier

A proof of principle of a novel concept for event recording in dual-phase liquid xenon detectors -- the Floating Hole Multiplier (FHM) -- is presented. It is shown that a standard Thick Gaseous Electron Multiplier (THGEM), freely floating on the liquid xenon surface permits extraction of electrons from the liquid to the gas. Secondary scintillation induced by the extracted electrons in the THGEM holes as well as in the uniform field above it was observed. The first results with the FHM indicate that the concept of floating electrodes may offer new prospects for large-scale dual-phase detectors, for dark matter searches in particular.

physics.ins-det↗

arXiv2022

A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector.

physics.ins-det↗

arXiv2021

Bubble dynamics in Liquid Hole Multipliers

In bubble-assisted Liquid HoleMultipliers(LHM), developed for noble-liquid radiation detectors, the stability of the bubble and the electro-mechanical properties of the liquid-to-gas interface play a dominant role in the detector performance. A model is proposed to evaluate the static equilibrium configurations of a bubble sustained underneath a perforated electrode immersed in a liquid. For the first time bubbles were optically observed in LAr; their properties were studied in contact with different material surfaces. This permitted investigating the bubble-electrodynamics via numerical simulations; it was shown that the electric field acts as an additional pressure term on the bubble meniscus. The predictions for the liquid-to-gas interface were successfully validated using X-ray micro-CT in water and in silicone oil at STP. The proposed model and the results of this study are an important milestone towards understanding and optimizing the parameters of LHM-based noble-liquid detectors.

physics.ins-det↗

arXiv2020

Solar Neutrino Detection Sensitivity in DARWIN via Electron Scattering

We detail the sensitivity of the liquid xenon (LXe) DARWIN observatory to solar neutrinos via elastic electron scattering. We find that DARWIN will have the potential to measure the fluxes of five solar neutrino components: $pp$, $^7$Be, $^{13}$N, $^{15}$O and $pep$. The precision of the $^{13}$N, $^{15}$O and $pep$ components is hindered by the double-beta decay of $^{136}$Xe and, thus, would benefit from a depleted target. A high-statistics observation of $pp$ neutrinos would allow us to infer the values of the weak mixing angle, $\sin^2θ_w$, and the electron-type neutrino survival probability, $P_e$, in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, at an exposure of 300 ty. An observation of $pp$ and $^7$Be neutrinos would constrain the neutrino-inferred solar luminosity down to 0.2%. A combination of all flux measurements would distinguish between the high (GS98) and low metallicity (AGS09) solar models with 2.1-2.5$σ$ significance, independent of external measurements from other experiments or a measurement of $^8$B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, we demonstrate that with a depleted target DARWIN may be sensitive to the neutrino capture process of $^{131}$Xe.

physics.ins-det↗

arXiv2019

Bubble-assisted Liquid Hole Multipliers in LXe and LAr: towards "local dual-phase TPCs"

The bubble-assisted Liquid Hole Multiplier (LHM) is a novel concept for the combined detection of ionization electrons and scintillation photons in noble-liquid time projection chambers. It consists of a perforated electrode immersed in the noble liquid, with heating wires generating a stable bubble underneath. Radiation-inducted ionization electrons in the liquid drift into the electrode's holes and cross the liquid-vapor interface into the bubble where they induce electroluminescence (EL). The top surface of the electrode is optionally coated with a CsI photocathode; radiation-induced UV-scintillation photons extract photoelectrons that induce EL in a similar way. EL-photons recorded with an array of photosensors, e.g. SiPMs, provide event localization. We present the basic principles of the LHM and summarize the results obtained in LXe and LAr.

physics.ins-det↗