Joint Institute for Nuclear Research
Recent publications
We describe the formation of swift heavy ion tracks in polyethylene (PE) by combining the Monte Carlo code TREKIS, which models electronic excitation in nanometric proximity of the ion trajectory, with the molecular dynamics simulating a response of the atomic system to the excitation. The model predicts circular tracks in amorphous PE but elliptical ones in crystalline PE caused by preferential propagation of excitation along polymer chains during the cooling stage. The obtained track sizes and shapes agree well with the high-resolution transmission microscopy of tracks in PE with colorant. The velocity effect in PE is shown: the track parameters differ for ions with the same linear energy losses but different velocities. Graphical abstract
The super τ -charm facility (STCF) is an electron–positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 10 ³⁵ cm ⁻² ·s ⁻¹ or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ -charm factory — the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics case studies.
The next years will see the completion of several new facilities at Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud (LNS) opening up new possibilities in the fields of nuclear structure, nuclear dynamics, nuclear astrophysics and applications. These include a new line for high-intensity cyclotron beams, a new facility for in-flight production of radioactive ion beams, the PANDORA plasma trap for multidisciplinary studies and a high-power laser for basic science and applied physics. The nuclear physics community has organized a workshop to discuss the new physics opportunities that will be possible in the middle term (5–7 years) by employing state-of-the-art detection systems. A detailed discussion of the outcome from the workshop is presented in this report.
Binary and ternary multilayers comprising paramagnetic and ferromagnetic materials filter out a specific neutron wavelength from the reflected broad spectrum. The effect of the grazing angle, the magnetization of the ferromagnetic layers and the scattering length density of the ferromagnetic layers for both structures are studied. The best performance of the proposed filter, such as the broadest neutron bandgap of 0.46 Å and the smallest bandwidth of the transmitted beam of 0.0016 Å, was achieved using the binary structure at magnetization of 40 kOe. These findings hold potential in the nuclear fields, including neutron waveguides and filters.
In this study, we investigated the production of Au isotopes through neutron transfer reactions in the $^{48}$Ca + $^{197}Au collision at a beam energy of 300 MeV. The reaction products of $^{197\pm x}$Au were captured and stopped within an assembly of Au targets after being irradiated with a $^{48}$Ca beam. The populated Au isotopes were identified through gamma decay spectroscopy and production cross- sections were determined. Furthermore, we performed model calculations based on the solution of the time-dependent Schrödinger equation for neutrons. These calculations aimed to estimate the formation probabilities and cross-sections of the measured Au isotopes and to elucidate the dynamics of the neutron transfer process. To describe the cross sections of neutron transfer channels and compare with the results of calculations within the framework of the model based on the time-dependent Schrödinger equation, calculations using the Grazing code were performed.
The Laetoli hominid footprints dating back some 3.6 million years discovered by Leakey in 1978 is an archaeological site of great importance in understanding the human evolution. The footprints of hominids, animals, and birds cast in the volcanic ash consolidated into tuff deposits are also an insight into the evolution of the whole biogeosystem of this area dominated by volcanic activity. The volcanic ash deposits consolidated into tuffs are a marker which sets the base line for tracking the further sediment transport in the catchment of this historic site. The surface of the tuff exposure along the Garusi river carrying the footprints shows no signs of weathering and the soils of the area form in subsequent sediments that filled the valley after the deposition of the tuff material. Following the deposition and consolidation of the airfall tuffs, the biogeosystem of the Laetoli gorge and its surroundings experienced a complex evolution which led to formation of the present-day soil cover. The study of clay mineralogy of these soils has provided interesting insights into the evolution of this system.
Resistance to chemo- or radiotherapy is the main obstacle to consistent treatment outcomes in oncology patients. A deeper understanding of the mechanisms driving the development of resistance is required. This review focuses on secretory factors derived from chemo- and radioresistant cancer cells, cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), and cancer stem cells (CSCs) that mediate the development of resistance in unexposed cells. The first line of evidence considers the experiments with conditioned media (CM) from chemo- and radioresistant cells, CAFs, MSCs, and CSCs that elevate resistance upon the ionizing radiation or anti-cancer drug exposure of previously untreated cells. The composition of CM revealed factors such as circular RNAs; interleukins; plasminogen activator inhibitor; and oncosome-shuttled lncRNAs, mRNAs, and miRNAs that aid in cellular communication and transmit signals inducing the chemo- and radioresistance of sensitive cancer cells. Data, demonstrating that radioresistant cancer cells become resistant to anti-neoplastic drug exposure and vice versa, are also discussed. The mechanisms driving the development of cross-resistance between chemotherapy and radiotherapy are highlighted. The secretion of resistance-mediating factors to intercellular fluid and blood brings attention to its diagnostic potential. Highly stable serum miRNA candidates were proposed by several studies as prognostic markers of radioresistance; however, clinical studies are needed to validate their utility. The ability to predict a treatment response with the help of the miRNA resistance status database will help with the selection of an effective therapeutic strategy. The possibility of miRNA-based therapy is currently being investigated with ongoing clinical studies, and such approaches can be used to alleviate resistance in oncology patients.
La2O3 nanoparticles stabilized on carbon nanoflake (CNF) matrix were synthesized and graphitized to produce core-shell structures La2O3/CNFs@C. Further oxidation of these structures by nitric acid vapors for 1, 3 or 6 h was performed, and surface-oxidized particles La2O3/CNFs@C_x (x = 1, 3, 6) were produced. Bulk and surface compositions of La2O3/CNFs@C and La2O3/CNFs@C_x were investigated by thermogravimetric analysis and X-ray photoelectron spectroscopy. With increasing the duration of oxidation, the oxygen and La2O3 content in the La2O3/CNFs@C_x samples increased. The electronic structures of samples were assessed by electron paramagnetic resonance. Two paramagnetic centers were associated with unpaired localized and mobile electrons and were registered in all samples. The correlation between bulk and surface compositions of the samples and their electronic structures was investigated for the first time. The impact of the ratio between sp2- and sp3-hybridized C atoms, the number and nature of oxygen-containing groups on the surface and the presence and proportion of coordinated La atoms on the EPR spectra was demonstrated.
The low- x behavior of the linearly polarized gluon density h g ( x , $$k_{t}^{2}$$ , Q ² ) in nuclei is studied in the rescaling model at small transverse momentum k t .
The microscopic calculation of the decay width of giant monopole resonance (GMR) anticipates the mixing of one-phonon states with configurations of increasing complexity. To this aim we develop the effective approach for description of monopole excited states that are obtained in the quasiparticle random phase approximation (QRPA), with regard of the coupling between one- and two-phonon states. Based on the QRPA one-phonon states, we generate the coupling and two-phonon states by means of the Gaussian orthogonal ensemble (GOE) distribution. Within our approach the spreading width of the GMRs in 204,206,208 Pb are described by means of a random matrix approach on two energy scales. It is demonstrated that the main contribution into the decay of the GMR is determined by a small number of two-phonon states strongly coupled to low-energy surface vibrations. While a vast majority of the coupling matrix elements (that are small in value and following the GOE distribution) are responsible for the fine structure of the GMR spreading width. A remarkable agreement between the results of the full microscopic calculations (based on QRPA phonons coupled by means of the microscopic coupling matrix elements with calculated two-phonon states) with those of the developed approach confirms the vitality of the proposed ideas.
JEM-EUSO is an international program for the development of space-based Ultra-High Energy Cosmic Ray observatories. The program consists of a series of missions which are either under development or in the data analysis phase. All instruments are based on a wide-field-of-view telescope, which operates in the near-UV range, designed to detect the fluorescence light emitted by extensive air showers in the atmosphere. We describe the simulation software ESAF in the framework of the JEM-EUSO program and explain the physical assumptions used. We present here the implementation of the JEM-EUSO, POEMMA, K-EUSO, TUS, Mini-EUSO, EUSO-SPB1 and EUSO-TA configurations in ESAF. For the first time ESAF simulation outputs are compared with experimental data.
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1,170 members
Vadim A. Naumov
  • Bogoliubov Laboratory of Theoretical Physics
Shakir Zeynalov
  • Frank Laboratory of Neutron Physics
Alexander Bakulev
  • Bogoliubov Laboratory of Theoretical Physics
Krassimira Petrova Marinova
  • Laboratory of Nuclear Reactions
Jordan Brankov
  • Bogoliubov Laboratory of Theoretical Physics
Dubna, Russia
Head of institution
V.A. Matveev
+749621 65059