Physics of Particles and Nuclei Letters最新文献

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and other spin-related phenomena using polarized beams. Two Beam-Beam Counters (BBCs) will be installed symmetrically aside from the interaction point in the end-cups of SPD setup and will serve as a tool for beam diagnostics including local polarimetry. The outer part of the BBC wheel is based on fast scintillator tiles and cover the polar angels between 60 and 500 mrad. Different material configurations for the BBC prototype based on scintillator tiles were tested. The light collection depends on material combinations—fiber (Saint Gobain BCF91AS, BCF92S, and Kuraray Y-11), tile surface cover (Matted and double covered with Tyvek sheets tiles), and optical cement (CKTN mark E, OK-72). SensL 1 ( times ) 1 mm² and 3 ( times ) 3 mm² SiPMs were used as photosensors in the prototype tiles. The studies were performed with a cosmic rays test setup equipped with CAEN FERS-5200 readout system.

Abstract

A huge amount of experimental data should be collected, stored and processed in large modern high-energy physics experiments, including the experiments of the NICA (Nuclotron-based Ion Collider fAcility) project at the Joint Institute for Nuclear Research. In this regard, corresponding performance requirements are put forward for existing online systems. The online data processing system developed for the BM@N experiment within the NICA project is based on a distributed architecture, enabling it to meet high performance requirements through scalability and parallel computing. The purpose of the online system is selective data processing (conversion to event digits in the CERN ROOT format and fast event reconstruction) and data monitoring of the ongoing experiment. To achieve this goal, the FairMQ package implemented by the FAIR collaboration (GSI Institute, Germany) has been chosen to communicate distributed processes executed on the nodes of the computing infrastructure with each other through the exchange of their messages. One of the issues in developing and using such systems is the problem of the distributed run and control of the processes. The task has been solved by using the FAIR DDS (Dynamic Deployment System) toolkit. The BM@N online system starts the predefined software tasks in a required sequence and allows managing them during sessions, including the transmission of messages between the tasks and the update of some properties. The paper presents the purposes and architecture of the Online Data Processing System for the BM@N experiment and features of the current implementation.

Abstract

This paper presents a study aimed at studying and evaluating the possibility of using machine learning in methods of predictive analysis of the operation of the cooling system of the IRT-T reactor. Machine learning is a subspecies of artificial intelligence used in large-volume data analytics. The currently existing methods of processing data on technological parameters are imperfect and do not allow predicting the development of operational events. The proposed approach will allow not only to centrally collect data on technological parameters, but also to output an analysis of possible outcomes and recommendations for changing operating modes.

Abstract

A method of theoretical modeling of the spectrum of interaction of an ultrashort laser pulse with a DNA macromolecule is presented. The method is based on the search for symmetric regions in the structure under study and makes it possible to reduce the calculation time for polyatomic objects.

Abstract

Transglutaminase 2 (TG2) is a pivotal enzyme involved in various biological processes such as wound healing, apoptosis, and cell differentiation. Depending on the environmental conditions, TG2 can adopt two distinct conformations: the open and closed states. Notably, the open conformation of TG2 has been associated with the pathogenesis of several diseases, including celiac disease and certain cancers. Recent investigations have demonstrated that within human cells, open-state TG2 can exist both as monomers and as dimers. The monomeric form primarily exhibits transamidation activity, whereas the dimeric form is postulated to exert cytotoxic effects. While several structures of the monomeric open-state TG2 are available in the Protein Data Bank, structures representing the dimeric form remain elusive. The objective of this study is to elucidate the structural distinctions between TG2 monomers and dimers using small-angle X-ray scattering (SAXS).

Abstract

Modern astronomy aims to study the astrophysical objects with the various types of signals incoming from them. To achieve the goals of the multi-messenger astronomy, experiments should exchange data, that can be done with the alert messages. Alert contains essential information about the detected event. These messages are distributed via international networks facilitating the rapid follow-up of transient astrophysical phenomena. The Baikal-GVD alert system receives external alerts and applies different methods to search for signal coincidences. For better understanding of the alert system workflow and researching of the astrophysical neutrino sources the alert visualization is necessary. This work deals with the techniques that are used within the coincidence search process and the visualization of the alerts: Baikal-GVD alerts and external messages from experiments like the IceCube neutrino telescope, Fermi gamma-ray telescope and LIGO/Virgo/KAGRA gravitational observatories.

Abstract

A prototype of a track scintillation detector has been developed, which is based on a cubic plastic scintillator with dimensions of 100 × 100 × 100 mm(^{3}). The detector is intended for imaging particle tracks using an array of SiPM photodetectors. The measurement methodology, the experimental stand, and the results obtained are presented.

Abstract

JINR is developing а novate cyclotron for proton therapy (including FLASH) for new JINR’s international biomedical research center. The project is about to be put into manufacturing stage. As unavoidable parts of this process, engineering, mechanical, and production limitations impose correction on the physical conceptual design of the cyclotron. Therefore, the initial extraction system, consisting of an electrostatic deflector followed by two magnetic channels with their compensators, was adjusted accordingly to the new model and improved for upcoming manufacturing stage.

Abstract

Metal oxide catalysts (MOCs) for the growth of carbon nanotubes with the general composition Fe₂Co/CaCO₃ were synthesized by the polymerized complex precursor (PCP) method using chelating agents. It has been established that metal oxide catalysts synthesized by the method of polymerized complex precursors are an order of magnitude more effective than MOCs synthesized by the sol-gel technology. The productivity of MOCs obtained using two ligands is significantly higher than the efficiency of monoligand samples. As a result of the study, it was found that the use, in addition to carbohydrates, of a wide range of chelating agents of various natures (polyalcohols, hydroxy acids, amino acids, etc.) in the synthesis of metal oxide catalysts for the growth of CNTs by the method of polymerized complex precursors is advisable and makes it possible to affect the stage of preorganization of the structure of MOCs precursor, specific productivity of metal oxide catalysts as well as qualitative composition of carbon products.

The process of multiple Compton scattering, (egamma to e(Ngamma )), is considered in a strongly magnetized, charge-asymmetric, cold electron-positron plasma. The special case of process—the Double Compton scattering is considered. The amplitudes for both processes are derived in the general case, where electrons can occupy arbitrary Landau levels. An expressions for the amplitude of the Double Compton process in the magnetar case have been obtained. The double Compton scattering under considered conditions is shown to be an efficient process for the production of polarized photons.