Orazaly Kalikulov

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events.

The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment with a rich physics program that includes searches for the hypothetical phenomenon of proton decay. Utilizing liquid-argon time-projection chamber technology, DUNE is expected to achieve world-leading sensitivity in the proton decay channels that involve charged kaons in their final states. The first DUNE demonstrator, ProtoDUNE Single-Phase, was a 0.77 kt detector that operated from 2018 to 2020 at the CERN Neutrino Platform, exposed to a mixed hadron and electron test-beam with momenta ranging from 0.3 to 7 GeV / c . We present a selection of low-energy kaons among the secondary particles produced in hadronic reactions, using data from the 6 and 7 GeV / c beam runs. The selection efficiency is 1% and the sample purity 92%. The initial energies of the selected kaon candidates encompass the expected energy range of kaons originating from proton decay events in DUNE (below ∼ 200 MeV ). In addition, we demonstrate the capability of this detector technology to discriminate between kaons and other particles such as protons and muons, and provide a comprehensive description of their energy loss in liquid argon, which shows good agreement with the simulation. These results pave the way for future proton decay searches at DUNE.

We have developed a homemade neutron flux detection module with 3He tube hot-swap capability and control-rich Android software interface. Real-time data analysis is done by a smartphone with Android application interfaced with the detector via a USB cable. This setup can be used as a neutron and gamma ray background detector or as a compact, mobile 3He tubes calibration tool making it a cheap and easy-to-use alternative for the stationary setups. A fast neutron detection algorithm was implemented as a set of Java scripts and tested for real-time signal analysis. The modular structure of the device allows easy deployment and customization with further software development and regular upgrades. The current prototype was tested at the Nuclear Physics Research Institute under different neutron flux intensity conditions from the VVR-K water-cooled research reactor. Its simplicity and significantly lower cost, compared with conventional detector equipment, make it valuable for easy repetitive tasks with medium requirements for precision and neutron flux intensities.

В работе представлен анализ события, зарегистрированного 1-10 июня 2025 г. нейтронным монитором AATB (Алматы, Казахстан, 3340 м над уровнем моря, жесткость геомагнитного обрезания R = 5.9 ГВ). Амплитуда понижения интенсивности космических лучей, зарегистрированной нейтронным монитором, составила около 12 %, что позволяет отнести событие к числу больших Форбуш-эффектов. Источником возмущений явилась активная область AR 14100, в которой произошла серия вспышек классов M3.4 и M8.1 (30–31 мая 2025 г.), сопровождавшихся быстрыми гало-CME корональными выбросами масс (КВМ) типа гало со скоростями до 1700 км/с. Сопоставление данных нейтронного монитора с межпланетными параметрами показало классическую структуру межпланетного КВМ, включающую межпланетную ударную волну 1 июня, 05:45 UT, область возмущенной сжатой плазмы и область коронального выброса до 2 июня, 01:10 UT. Событие сопровождалось развитием сильной геомагнитной бурей, пик которой пришёлся на 2 июня. Результаты демонстрируют тесную взаимосвязь между солнечной активностью, динамикой межпланетного КВМ и модуляцией потоков галактических космических лучей ГКЛ, подчёркивая значимость комплексного подхода к диагностике и прогнозированию космической погоды.

The High-Energy Ray Observatory (HERO) is a space-based experiment designed to measure the spectrum and composition of cosmic rays using an ionization calorimeter. The instrument’s effective geometric factor is at least 12 m²·sr for protons and 16 m²·sr or more for nuclei and electrons. Over an exposure period of approximately 5 to 7 years, the mission will enable high-resolution, element-by-element measurements of cosmic ray spectra in the energy range of 10¹² to 10¹⁶ eV per particle. A Monte Carlo simulation of the calorimeter—based on a scintillation detector with and without boron additives—was carried out using the GEANT4 software package. In this study, we examine the impact of boron additives in scintillator materials on energy resolution and their potential for discriminating between electromagnetic and hadronic components of cosmic rays. The primary objectives are to demonstrate that boron does not degrade detector characteristics and that it enables an additional timing-based method for cosmic-ray component rejection. The planned launch of the orbital experiment is scheduled for no earlier than 2029.

Liquid argon time projection chambers (LArTPCs) rely on highly pure argon to ensure that ionization electrons produced by charged particles reach readout arrays. ProtoDUNE Single-Phase (ProtoDUNE-SP) was an approximately 700-ton liquid argon detector intended to prototype the Deep Underground Neutrino Experiment (DUNE) Far Detector Horizontal Drift module. It contains two drift volumes bisected by the cathode plane assembly, which is biased to create an almost uniform electric field in both volumes. The DUNE Far Detector modules must have robust cryogenic systems capable of filtering argon and supplying the TPC with clean liquid. This paper will explore comparisons of the argon purity measured by the purity monitors with those measured using muons in the TPC from October 2018 to November 2018. A new method is introduced to measure the liquid argon purity in the TPC using muons crossing both drift volumes of ProtoDUNE-SP. For extended periods on the timescale of weeks, the drift electron lifetime was measured to be above 30 ms using both systems. A particular focus will be placed on the measured purity of argon as a function of position in the detector.

This review provides a comprehensive analysis of current trends in the development and application of scintillation materials for neutron detection. A bibliometric methodology was applied using structured keyword queries across major academic databases (Google Scholar, Scopus, and eLibrary) to evaluate over 350,000 publications. The search focused on four thematic dimensions: material types, physical properties, detection technologies, and applied uses. Key attention is given to high light-yield materials capable of pulse shape discrimination, including doped crystals (LaBr₃, CLYC, GAGG:Ce), hybrid systems, and fiberbased scintillators. Analysis of publications from 2020-2025 shows that nearly half of all literature has emerged in the last five years, confirming high research activity. English dominates as the primary language of dissemination, while Kazakh-language contributions remain absent. The findings support a four-fold classification framework and may serve as a strategic tool for material selection and detector development in nuclear monitoring, space missions, and radiation diagnostics.

The Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours.