DarkSide-20k is a novel liquid argon dark matter detector currently under construction at the Laboratori Nazionali del Gran Sasso (LNGS) of the Istituto Nazionale di Fisica Nucleare (INFN) that will push the sensitivity for Weakly Interacting Massive Particle (WIMP) detection into the neutrino fog. The core of the apparatus is a dual-phase Time Projection Chamber (TPC), filled with 50 tonnes of low radioactivity underground argon (UAr) acting as the WIMP target. NUV-HD-cryo Silicon Photomultipliers (SiPM)s designed by Fondazione Bruno Kessler (FBK) (Trento, Italy) were selected as the photon sensors covering two $$10.5~\text {m}^2$$ 10.5 m 2 Optical Planes, one at each end of the TPC, and a total of $$5~\text {m}^2$$ 5 m 2 photosensitive surface for the liquid argon veto detectors. This paper describes the Quality Assurance and Quality Control (QA/QC) plan and procedures accompanying the production of FBK NUV-HD-cryo SiPM wafers manufactured by LFoundry s.r.l. (Avezzano, AQ, Italy). SiPM characteristics are measured at 77 K at the wafer level with a custom-designed probe station. As of March 2025, 1314 of the 1400 production wafers (94% of the total) for DarkSide-20k were tested. The wafer yield is $$93.2\pm 2.5$$ 93.2 ± 2.5 %, which exceeds the 80% specification defined in the original DarkSide-20k production plan.

DarkSide-20k (DS-20k) is a dark matter detection experiment under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It utilises similar to 100 t of low radioactivity argon from an underground source (UAr) in its inner detector, with half serving as target in a dual-phase time projection chamber (TPC). The UAr cryogenics system must maintain stable thermodynamic conditions throughout the experiment's lifetime of over 10 years. Continuous removal of impurities and radon from the UAr is essential for maximising signal yield and mitigating background. We are developing an efficient and powerful cryogenics system with a gas purification loop with a target circulation rate of 1000 slpm. Central to its design is a condenser operated with liquid nitrogen which is paired with a gas heat exchanger cascade, delivering a combined cooling power of more than 8 kW. Here we present the design choices in view of the DS-20k requirements, in particular the condenser's working principle and the cooling control, and we show test results obtained with a dedicated benchmarking platform at CERN and LNGS. We find that the thermal efficiency of the recirculation loop, defined in terms of nitrogen consumption per argon flow rate, is 95% and the pressure in the test cryostat can be maintained within +/-(0.1-0.2) mbar. We further detail a 5-day cool-down procedure of the test cryostat, maintaining a cooling rate typically within -2K/h, as required for the DS-20k inner detector. Additionally, we assess the circuit's flow resistance, and the heat transfer capabilities of two heat exchanger geometries for argon phase change, used to provide gas for recirculation. We conclude by discussing how our findings influence the finalisation of the system design, including necessary modifications to meet requirements and ongoing testing activities.

The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV c(-2). This was demonstrated by the DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV c(-2) particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP-nucleon interaction cross-sections below 1x10(-42) cm(2) is achievable for WIMP masses above 800 MeV c(-2). With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV c(-2).

Experiments aimed at direct searches for WIMP dark matter require highly effective reduction of backgrounds and control of any residual radioactive contamination. In particular, neutrons interacting with atomic nuclei represent an important class of backgrounds due to the expected similarity of a WIMP-nucleon interaction, so that such experiments often feature a dedicated neutron detector surrounding the active target volume. In the context of the development of DarkSide-20k detector at INFN Gran Sasso National Laboratory (LNGS), several R D projects were conceived and developed for the creation of a new hybrid material rich in both hydrogen and gadolinium nuclei to be employed as an essential element of the neutron detector. Thanks to its very high cross-section for neutron capture, gadolinium is one of the most widely used elements in neutron detectors, while the hydrogen-rich material is instrumental in efficiently moderating the neutrons. In this paper results from one of the R Ds are presented. In this effort the new hybrid material was obtained as a poly(methyl methacrylate) (PMMA) matrix, loaded with gadolinium oxide in the form of nanoparticles. We describe its realization, including all phases of design, purification, construction, characterization, and determination of mechanical properties of the new material.

Owing to a change in the scope of physics research, the AMBER spectrometer at CERN is undergoing an update on its instrumentation and trigger strategy for the data acquisition system. One of the key updates is the adoption of a free-running and trigger-less operation, which differs from the predecessor of AMBER, COMPASS, by working in a continuous mode but in an event-based triggered way. In this article, we present a multichannel data-acquisition platform developed in line with the next generation of trigger-less and free-running data acquisition systems. The platform is based on a pre-existing Mezzanine Sampling ADC board for the analog-to-digital conversion and a Xilinx Zynq Ultrascale+ System on Module for online real-time data processing. We also present the evaluation of the system operating in continuous mode, taking data from a 25-element electromagnetic calorimeter prototype with a muon beam, during the first AMBER pilot run. The acquired data were used for noise and pulse shape studies required for the design of the algorithms for lossless compression and data feature extraction needed for trigger-less operation.

The aim of the paper is to present the distributed system for the unwanted event detection regarding inmates in the closed penitentiary facilities. The system processes large number of data streams from IP cameras (up to 180) and performs the event detection using Deep Learning neural networks. Both audio and video streams are processed to produce the classification outcome. The application-specific data set has been prepared for training the neural models. For the particular event types 3DCNN and YOLO architectures have been used. The system was thoroughly tested both in the laboratory conditions and in the actual facility. Accuracy of the particular event detection is on the satisfactory level, though problems with the particular events have been reported and will be dealt with in the future.

Hyper-Kamiokande (HK) is the next generation underground water Cherenkov detector that builds on the highly successful Super-Kamiokande (SK) experiment. The 260,000-ton detector has an 8.4 times larger fiducial volume than its predecessor. HK's low energy threshold combined with the very large fiducial volume make the detector unique; HK is expected to acquire an unprecedented exposure of 3.8 Mton-year over a period of 20 years starting in 2027. It has an extremely diverse science program including long-baseline neutrino oscillation measurements, nucleon decay searches, atmospheric neutrinos, neutrinos from the sun and supernova explosions, and neutrinos from other astrophysical origins. Like DUNE, the flagship project of the U.S. high-energy physics program, HK measures fundamental properties of neutrinos such as the search for leptonic CP violation and neutrino physics beyond the Standard Model.

This paper presents the interdisciplinary project aimed at detecting the undesired or dangerous behavior of persons in the confined institutions such as prisons or wards, based on the video streams provided by the CCTV cameras. Currently, there are IT systems working in such areas, but their efficiency is limited, forcing the operator to focus his/her attention on every image separately. Design of a system for autonomous detection of anomalous behaviors - such as fights or passing illegal material - based on the input from multiple surveillance cameras would allow for providing the decision support module. With the acceptable detection accuracy, the solution would help in minimizing the accidents and unwanted behavior of monitored inmates. The system should also provide the catalogue of predefined dangerous situations, prepared by the experts in criminal sciences, including the features useful for predicting the specific events.

Supernovae are among the most magnificent events in the observable universe. They produce many of the chemical elements necessary for life to exist and their remnants---neutron stars and black holes---are interesting astrophysical objects in their own right. However, despite millennia of observations and almost a century of astrophysical study, the explosion mechanism of supernovae is not yet well understood. Hyper-Kamiokande is a next-generation neutrino detector that will be able to observe the neutrino flux from the next galactic supernova in unprecedented detail. In this thesis, I investigate how well such an observation would allow us to reconstruct the explosion mechanism. I develop a high-precision supernova event generator and use a detailed detector simulation and event reconstruction to explore Hyper-Kamiokande's response to five supernova models simulated by different groups around the world. I show that 300 neutrino events in Hyper-Kamiokande---corresponding to a supernova at a distance of at least 60 kpc---are sufficient to distinguish between these models with high accuracy. These findings indicate that, once the next galactic supernova happens, Hyper-Kamiokande will be able to determine details of the supernova explosion mechanism.

This article discusses the construction of a prototype of a platform that provides the integration of video signals from multiple sources. Video sources can be both existing CCTV systems based on analog cameras, modern systems based on IP cameras and individual cameras of various types. The system consists of portable units that provide signal conversion, its encoding, video streaming and transmission over IP protocols. A distributed and modular prototype of the VSI system was developed. The system consists of modular devices that integrate video streams, user terminals and central system. The VSI prototype provides simultaneous access to a large number of real- time video streams . The system is fully modular, which enables easy expansion of both hardware and software. The article presents the obtained architecture and exemplary operating results.

The article presents selected results of research conducted by the consortium under the implemented project for national defense and security on “Video Signals Integrator" Acronym – VSI. Project Leader: Warsaw University of Technology. The consortium: Police Academy in Szczytno, Atende Software Ltd., VORTEX Ltd. No. DOB-Bio7/01/02/2015 funded by the National Centre for Research and Development. The essence of the Video Signals Integrator is to acquire and process signals from multiple sources: existing monitoring systems based on analog cameras, modern systems based on IP cameras, different types of individual cameras. The efficient functioning of the device depends on the properly prepared Configuration Database of the Central Video Integrator System. The configuration database contains information necessary to operate the system by users, both in the scope of authorizations (data of users who can use consoles of particular types) as well as sources of streams processed by the system. It also creates the possibility of grouping streams according to their source. This option allows the user to identify the sources of a given signal and the corresponding response. The functional requirements were taken into account in the development of the concept of Configuration Database. As a result of the research, a design of the pilot version of the VSI system will be created, along with complete server software and a full-sized user console.

The Video Concentration Device (VCD) is the component of the Video Signals Integrator (VSI). The whole VSI is a complex hybrid system containing hardware, firmware, and software components and can integrate and serve video signals from many sources. The VCD is a portable device capturing video signals in various formats from different sources, and transmitting them to the VSI server. Due to high complexity, VCD is equipped with a diagnostic system providing the possibility to remotely manage it. Its functions include the update of the firmware and software, starting the special diagnostic version of the firmware and the software, low-level expert access. In most cases it should eliminate the necessity of the on-site expert’s intervention, except in case of hardware failure

The paper describes the prototype implemetantion of the Video Signals Integrator (VSI). The function of the system is to integrate video signals from many sources. The VSI is a complex hybrid system consisting of hardware, firmware and software components. Its creation requires joint effort of experts from different areas. The VSI capture device is a portable hardware device responsible for capturing of video signals from different different sources and in various formats, and for transmitting them to the server. The NVR server aggregates video and control streams coming from different sources and multiplexes them into logical channels with each channel representing a single source. From there each channel can be distributed further to the end clients (consoles) for live display via a number of RTSP servers. The end client can, at the same time, inject control messages into a given channel to control movement of a CCTV camera.

The emerging 3D television systems require effective techniques for transmission and storage of data representing a 3-D scene. The 3-D scene representations based on multiple video sequences or multiple views plus depth maps are especially important since they can be processed with existing video technologies. The review of the video coding and transmission techniques is presented in this paper.

The analysis of the compression methods of the stripe patterns video sequences used in structured light technique is presented in this paper. It has been shown that the illumination of the 3-D scene be the sequentially repeating stripe patterns introduces additional correlation to the structured light video sequence. The experimental results presented in this paper confirm that this correlation can be effectively utilized for the video encoding.

The framework for testing video streaming techniques is presented in this paper. Short review of error resilience and concealments tools available for the H.264/AVCstandard is given. The video streaming protocols and the H.264 payload format are also described. The experimental results obtained with the framework are presented in this paper too.