A critical element in the realization of large liquid and gas time projection chambers (TPCs) is the delivery and distribution of high voltages into and around the detector. Such experiments require of order tens of kilovolts to enable electron drift over meter-scale distances. This paper describes the design and operation of the cathode feedthrough and high voltage distribution through the field cage of the NEXT-100 experiment, an underground TPC that will search for neutrinoless double beta decay 0νββ. The feedthrough has been demonstrated to hold pressures up to 20 bar and sustain voltages as high as -65 kV. The TPC is operating stably at its design high voltages. The system has been realized within the constraints of a stringent radiopurity budget and is now being used to execute a suite of sensitive double beta decay analyses.

The CYGNO collaboration is developing a novel strategy for directional Dark Matter searches based on a gaseous Time Projection Chamber (TPC). The detector is optimized for the exploration of light (0.5–50 GeV) WIMPs-like particles and employs a He/CF4 gas mixture at atmospheric pressure, sensitive to both spin-dependent and spin-independent interactions. A key feature of the project is its optical readout, which relies on photon detection rather than charge collection. In CYGNO detectors, electrons released by ionizing tracks drift toward an amplification stage of three Gas Electron Multipliers (GEMs). The electron avalanches generate scintillation light that is captured by scientific CMOS (sCMOS) cameras for high-resolution two-dimensional imaging and by Photomultiplier Tubes (PMTs) that provide a precise time profile along the drift direction. This allows a 3D event reconstruction, detailed energy deposition mapping, and effective topology and head-to-tail discrimination. Building on the achievements of the 50 L prototype (LIME), which successfully operated underground at LNGS, the next step is the deployment of a 0.4 m3 demonstrator, CYGNO-04, to be completed in 2026. The demonstrator will validate scalability and confirm the advantages of the proposed technique. Recent results from LIME highlight strong progress in 3D tracking and particle identification. The current status of CYGNO-04 and its role in advancing the program will be presented as well.

The DarkSide-20k experiment, currently under construction at LNGS, will employ a next-generation dual-phase liquid-argon Time Projection Chamber (TPC) with SiPM-based Photon Detector Units and low-background materials to achieve the ambitious goal of operating with an instrumental background close to zero.Proto-0 is a small-scale dual-phase argon TPC operated at INFN Naples, designed to validate the integration of DarkSide-20k key technologies in a realistic detector environment and to study charge extraction and electroluminescence signal formation.In this short paper, we report on the early operation of Proto-0 and its single-phase commissioning. We focus on the measurement of the scintillation light yield using external and internal calibration sources.

Physics-informed continuous normalizing flows to learn the electric field within a time-projection chamber

We developed a cryogenic photon readout system to monitor arrays of DUNE SiPMs operating at various over-voltages in liquid nitrogen (LN2) for over three months. Photoelectron signals were read out simultaneously via weak capacitive coupling to the μFEMB, a 32-channel charge sensitive readout board designed for 77 K to 300 K operation in liquid argon time projection chambers (LAr-TPCs). A waveform snippet acquisition scheme was implemented to capture waveform signals whenever they exceeded a predetermined trigger level; consequently, empty waveforms were discarded. Selected SiPM parameters were monitored to detect any deviations beyond statistical fluctuations. While some parameters exhibited ∼ 1σ variations over the 3-month test period, there was no evidence of drift being enhanced when operating at 4 V or 5 V compared to a 3 V over-voltage. However, a discernible PDE drop was observed across all channels, which warrants further investigation. In addition, we demonstrated that our system can simultaneously read out single photons from a selected group of SiPMs at room temperature.

Gaseous Time Projection Chambers with Optical Readout are sensitive detectors suitable for 3D measurement of low-energy particles (of order 1 keV) and are proposed for detecting rare events such as Dark Matter particle interactions. The CYGNO collaboration is developing such a detector with a high spatial and energy resolution, leveraging an innovative optical readout system. A reliable simulation of the detector response is needed to properly assess the physics reach of this technique and to better understand the performance of the detector in the development phase. Such a simulation cannot entirely rely on existing software packages; indeed, none of the available tools is capable of properly and reliably treating the different phenomena occurring in the detector, from the primary interaction in the gas volume throughout the whole detector response model, including charge transport, light production and propagation, and the response of the optical sensors. In this paper, we present a modeling of the detector response tuned on the CYGNO Optical TPC case; a description of the method is reported together with comparisons with experimental data from the LIME prototype to demonstrate the simulation performances.

The PandaX-xT is a next-generation experiment with broad scientific goals, including the search for dark matter, Neutrinoless Double Beta Decay, and astrophysical neutrinos, using a dual-phase time projection chamber with about 43 tons of liquid xenon. A new cryogenics system of the PandaX-xT is described in this paper. It is developed to handle large mass of liquid xenon efficiently and safely, including two cooling towers for normal operation and one liquid-nitrogen coil for emergency case. Each cooling tower equipped with an AL600 Gifford-McMahon cryocooler features a 1300 W heater, specifically designed to maintain the cold finger's temperature at the desired setpoint. The performance of the cooling tower and the coil has been tested. The cryogenics system with two cooling towers has achieved about 1900 W cooling power at 178 K. The liquid nitrogen coil provides emergency cooling power of more than 1500 W at liquid xenon temperature. For the prototype of a 1-tonne liquid xenon detector, the fluctuation of xenon saturated vapor pressure remains below 1 kPa over one month, while the pressure is around 210 kPa.

Differential cross sections for 12C(n,α0), 16O(n,α0) and 16O(n,α1,2,3) between En = 7.2 and 10 MeV with an active-target time projection chamber

We present a real-time anomaly detection framework for liquid argon time projection chambers (LArTPCs), targeting applications in particle physics experiments such as the Short Baseline Near Detector or the future Deep Underground Neutrino Experiment. These experiments employ detectors that generate and stream high-resolution but sparse images of neutrino and other particle interactions. Our approach utilizes anomaly detection with autoencoders, compressed through knowledge distillation, to enable the detection of anomalous signals in the data through efficient inference on resource-constrained hardware. The framework is targeted for deployment on computing platforms equipped with field-programmable gate arrays, GPUs, or CPUs, allowing low-latency selection of relevant activity directly from the raw detector data stream. We demonstrate that our approach is suitable for the detection and localization of anomalously “high-multiplicity” activity, and outline promising applications for LArTPC online data filtering and triggering.

Large liquid argon time projection chambers (LArTPCs) require stable and well-characterized delivery of ultraviolet (UV) light for in situ calibration of photosensors at cryogenic temperatures. This article reports bench-top and cryogenic measurements of the optical components used in a UV light calibration system, including multi-mode fused-silica fibers, SMA-to-SMA connectors, optical fiber feedthroughs, and light-diffuser assemblies. Light loss in several fiber types and SMA connectors was measured across wavelengths from 275–970 mm. In addition, light-loss measurements of the tested fibers after several liquid-nitrogen thermal cycles showed no statistically significant degradation relative to baseline measurements, and high-rate pulsed exposure (30–90 million pulses from a 275 nm LED) likewise showed no measurable aging in jacketed fibers. A compact, palm-sized, 3D-printed PEEK diffuser housing with stacked UV-grade fused-silica diffusers yields Lambertian emission and the most uniform angular distribution. Optical components exhibiting improved UV transmission were deployed successfully in multiple DUNE small- and large-scale prototypes, demonstrating reliable operation of UV light calibration system. These findings inform component selection and calibration procedures for achieving reliable, uniform UV light delivery in large-scale cryogenic detectors such as DUNE.

Future e+e- collider projects, such as the International Linear Collider (ILC), the Circular Electron Positron Collider (CEPC), and the Future Circular Collider (FCC-ee), require the development of high performance main tracking detectors. Time Projection Chambers represent an attractive option for large-volume tracking systems in these experiments. To meet the demanding physics requirements, the detector concept foresees a large scale three dimensional tracking system based on a TPC operating in a 3.0 T solenoidal magnetic field, with a target spatial resolution of about 100 μm. The detector must also achieve a longitudinal position resolution of a few hundred micrometers while providing excellent particle identification (PID) performance with a resolution better than 3%. To address these requirements, a high granularity readout TPC technology has been developed. The feasibility of this approach for the CEPC has been investigated through detailed simulations, including studies at the low luminosity Z operation. The critical detector performance such as spatial resolution, drift velocity, and PID efficiency through cluster counting has been systematically evaluated. Compared with the conventional large pad readout, TPC detector with the high granularity readout delivers the good spatial resolution, high tracking efficiency and robust PID capabilities.

Direct detection dark matter experiments have proven to be compelling probes for studying low-energy neutrino interactions with both nuclei and atomic electrons, offering complementary information to accelerator and reactor-based neutrino experiments. Recently, the XENONnT and PandaX-4T collaborations reported the first evidence of coherent elastic neutrino-nucleus scattering from 8B solar neutrinos.Thanks to their excellent background rejection capabilities and distinctive signal signatures, dual-phase time projection chambers are also sensitive to pp solar neutrinos via their elastic scattering off atomic electrons in the target material. Although this signal is subdominant within the Standard Model, it becomes significantly enhanced in many beyond the Standard Model scenarios, offering a unique opportunity to probe new physics in the low-energy regime.In this work, we analyze the latest electron recoil and nuclear recoil data from XENONnT, PandaX-4T, and LUX-ZEPLIN to probe Standard Model and Beyond the Standard Model physics.While the precision of current neutrino measurements from such detectors remains lower than that achieved by dedicated neutrino experiments, their sensitivity to the tau neutrino component of solar neutrinos helps complete the overall picture, especially when investigating flavor-dependent new physics effects.

Large volumes of liquid argon or xenon constitute an excellent medium for the detection of Neutrino interactions and for Dark Matter searches. Traditionally, noble liquid detectors use scintillation light for a timing or calorimetric signal, read out in a time projection chamber configuration, where the liquid is permeated by an electric field.A direct optical reconstruction of the events though the imaging of scintillation light may offer an alternative to charge collection, removing the need for an electric drift field and the associated high-voltage hardware.Using finely segmented silicon photomultipliers arrays and a suitable optical system, it becomes possible to construct cameras that effectively “photograph” the primary scintillation light.A major challenge arises from the fact that both argon and xenon scintillate in the vacuum-ultraviolet range. To address this, we employ coded aperture masks in place of traditional lenses, enabling thin cameras with wide and deep field of view. A reconstruction algorithm based on Maximum Likelihood Expectation Maximization has been developed to obtain a 3D map of energy deposition, outperforming traditional deconvolution techniques in simulation under low-light conditions. The latest results from simulation and reconstruction of neutrino interactions in a liquid argon detector equipped with these cameras will be presented.

DarkSide-20k (DS-20k) is a next-generation dual-phase liquid argon (LAr) time projection chamber (TPC) devoted to the direct-detection of dark matter. The detector is currently under construction in Hall-C at the Laboratori Nazionali del Gran Sasso, Italy, at a depth of approximately 3500 m water equivalent. The detector will instrument 49.7 t of low-radioactivity underground LAr contained within an acrylic TPC and is designed to reach a WIMP-nucleon spin-independent cross-section sensitivity down to 10-48 cm2 for a WIMP mass of 0.1 TeV/c2 in a 200 tonne-year run. In DS-20k a uniform electric drift field is established in the active volume to transport ionization electrons toward the electroluminescence region, with the required high voltage delivered to the TPC cathode through an custom cable and stress-cone assembly.At University of California, Davis, a dedicated test setup was developed to reproduce the DS-20k cathode high-voltage connection in LAr, matching the local electric-field conditions.This work summarizes the results of a comprehensive test campaign validating the operation of the DS-20k cathode HV system in LAr up to -100 kV.

Liquid argon time projection chambers have emerged as a competitive technology for detecting solar neutrinos. The SoLAr collaboration was formed to explore argon detectors with pixelated light and charge readout, aiming for high detection efficiency and improved energy resolution. Building on the success of an initial prototype, we present results obtained with a second SoLAr prototype (V2), a 30 × 30 × 30 cm3 time projection chamber operated in a cryostat containing several hundred kilograms of liquid argon. We report measurements of cosmic-ray muons using both tracking and calorimetry from light and charge sensors, and we highlight the improved performance achieved through combined charge and light reconstruction. These results demonstrate the promise of dual-readout detectors and motivate future prototyping efforts toward kiloton-scale facilities.

The next-generation of neutrinoless double beta decay (0νββ) searches are targeting half-life sensitivities towards 1027–1028 years. Gaseous xenon time projection chamber (GXeTPC) detectors may be able to meet this challenge due to their excellent energy resolution and background rejection power through event visualization. This paper explores how the design choices of a next-generation GXeTPC time projection chamber can impact the overall performance of the experiment. We study the performance of systems using xenon enriched in the isotope 136Xe or natural xenon, focusing on scenarios that incorporate one tonne of 136Xe isotope. The detector size, copper shielding mass, energy resolution, density (using pressure at 293 K for convenience), and corresponding levels of diffusion are surveyed to evaluate the overall performance dependencies on these parameters. A detector optimized for using enriched xenon is preferred over natural, due primarily to a factor of 10 lower background rate driven by the large intrinsic backgrounds introduced by the copper shielding used in the detector. The performance of three types of gas TPC technologies was also explored based on different gas additives used to reduce diffusion to different levels. For all TPC technologies, we find background rates of a fraction of a count per tonne year in the region of interest are achievable. These performance levels are contingent on suitable energy resolution and event position placement in the drift direction being achieved for the specific detector technology. Performance for enriched xenon TPCs varies mildly with pressure in the range 5 to 25 bars, reaching background levels below 0.2 events/tonne-year. Performance at one bar is worse by approximately a factor of four. When considerations for the construction of the detector in addition to the selection performance are included, there may be no clearly optimum pressure.

The CYGNO experiment employs an optical readout to image particle interactions in a gaseous Time Projection Chamber (TPC), combining cameras and photomultiplier tubes (PMTs) to achieve high spatial resolution and timing information. This approach enables detailed track reconstruction but poses significant challenges for data acquisition, particularly in view of the next experimental phase, CYGNO-04, which will operate multiple cameras simultaneously. In this paper, we present an upgrade of the CYGNO Trigger and Data Acquisition (T-DAQ) system, developed starting from the LIME configuration and validated on the MANGO prototype. The upgrade introduces a continuous imaging acquisition mode, substantially reducing the camera dead time, together with an extended trigger time-tagging scheme that provides a robust global time reference for PMT signals. A synchronous multi-camera DAQ architecture is also implemented and tested, enabling coordinated operation of multiple optical sensors without a master camera. The performance of the upgraded system is validated through dedicated tests, demonstrating stable continuous acquisition, reliable time-tagging, and consistent synchronization across multiple cameras. These results establish a solid and scalable foundation for the CYGNO-04 DAQ and represent a key step toward efficient data acquisition in future large-scale optical TPC detectors.

Liquid xenon time projection chambers offer a homogeneous detection medium with excellent intrinsic energy resolution, fast scintillation, and true three-dimensional position sensitivity, making them an attractive alternative to crystal-based detectors for positron emission tomography (PET). In this work, we present a new single-phase liquid xenon time projection chamber (TPC) concept optimized for medical imaging, employing combined scintillation and electroluminescence-based ionization readout to enable low-noise signal amplification and intrinsic depth-of-interaction measurement.We evaluate the system-level performance of this detector concept using Monte Carlo simulations based on OpenGATE and Geant4, with direct comparison to conventional LYSO-based PET systems. The study focuses on detection sensitivity, energy-based event selection efficiency, and reconstructed spatial resolution. While LYSO detectors provide higher absolute stopping efficiency due to their higher density, liquid xenon detectors exhibit improved photopeak purity as a result of superior intrinsic energy resolution, leading to enhanced rejection of scattered events.Point-source reconstruction studies demonstrate that the intrinsic three-dimensional position sensitivity of the liquid xenon TPC translates into a reconstructed spatial resolution of approximately 1 mm full width at half maximum (FWHM) at the system level, compared to approximately 4 mm for LYSO-based systems under comparable conditions. These results indicate that liquid-xenon-based PET detectors can achieve competitive or superior imaging performance, particularly for applications requiring high spatial resolution, large axial acceptance, and scalable detector geometries.

For LHC Run 3, the ALICE Time Projection Chamber was upgraded to operate in continuous readout mode. Interaction rates of up to 50 kHz in Pb-Pb collisions require real-time processing of more than 3 TB s-1 of raw detector data. This requirement is met by a custom FPGA-based processing pipeline that performs the complete front-end data treatment fully in-stream, including common-mode correction, pedestal subtraction, ion-tail filtering, zero suppression, and dense data packing. A central element of the design is a highly parallel common-mode correction algorithm operating directly on the streaming data. It robustly identifies signal-free readout channels on a time-bin basis and applies pad-dependent scaling to compensate for local variations in capacitive coupling in the GEM readout. In combination with pedestal subtraction and ion-tail filtering, this enables accurate baseline restoration under extreme high-occupancy conditions, preventing signal loss while efficiently suppressing noise prior to zero suppression. The pipeline operates continuously at the full detector bandwidth and reduces the raw input rate of approximately 3 TB s-1 to about 900 GBps for Pb-Pb collisions at the target interaction rate. Overall, it represents a large-scale FPGA-based real-time signal-processing implementation for high-energy physics detector readout.

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline experiment for neutrino physics currently under construction in the US, aiming to measure neutrino oscillation parameters, search for beyond standard model physics and detect supernova neutrinos. DUNE will include a Near Detector (ND) and a Far Detector (FD), located 1300 km away from the ND and 1.5 km underground. The FD will consist of four 17-kton Liquid argon Time Projection Chambers (LArTPCs). In Phase I, two FD modules implementing horizontal (HD) and vertical (VD) drift technologies will be used. To test these technologies, two 750-ton LArTPCs (ProtoDUNEs) were built at CERN and were operated over the past two years.In particular, the FD Photon Detection System (PDS) is critical for the DUNE physics program. The topology of a neutrino interaction in the LArTPC is reconstructed from the tracks of secondary charged particles, which produce scintillation light and ionization charge carriers during their propagation in LAr. The reference time of the event is provided by the scintillation light, detected by X-ARAPUCA modules, i.e. photon traps consisting of a box with highly reflective internal walls instrumented with an array of Silicon PhotoMultipliers (SiPMs).In this paper, the designs of the DUNE PDS of the first two modules are presented, along with firstresults from ProtoDUNE-HD and ProtoDUNE-VD PDS operations. The preliminary results demonstrate thesuccessful operation of the PDS, marking a crucial step toward validating the horizontal andvertical drift designs for the first FD modules.