The propagation of relativistic electrons and muons within multilayer structures is considered. The Geant4 model of X-ray transition radiation (the yield of photons, their angular and spectral ...distributions, and the spectrum absorbed by a gas detector) is compared to experimental and RADIATOR data. It is demonstrated that the Geant4 spectral and, even more so, angular distributions differ from the experimental ones.
Research on the use of photonuclear reactions in the production of isotopes for nuclear medicine is reviewed. The review includes the analysis of distinctive features of isotope production in ...electron accelerators and assessment of the possibility of such production. The review also presents the results of experimental studies on the production of short-lived
18
F,
47
Sc, and
67
Cu radioisotopes with significantly high total activities in a split microtron with the electron energy of ~55MeV and the separation of
18
F and
67
Cu with high specific activities from the targets.
The work is aimed at studying the reliability of proton-induced neutron yield cross sections on
12
C–
127
I biological tissue isotopes using the GEANT4 Monte Carlo simulation package, which is ...commonly applied for dosimetry calculations in proton therapy. Because of the lack of experimental results on the neutron yield for most of the isotopes considered, the simulated cross sections are first compared with theoretical data acquired using the TALYS nuclear reaction package, and the partial reaction cross sections calculated in TALYS are in turn analyzed in comparison with available experimental results. The mismatch between theory and experiment allows one to suggest a significant uncertainty in the calculation of the neutron doses associated with the isotopes under consideration.
To realize the simulation experiments with the use of two ion beams at the injection complex of the BELA accelerator (Based on ECR ion source Linear Accelerator), it is necessary to determine the ...energy and irradiation angle of the beam of light ions which will be implanted into the region of radiation damage induced by heavy-ion beam. The depth of light-ion implantation is determined by the energy and kind of particles initiating the damage, as well as by their incidence angle. It is supposed that the incidence direction of heavy ions will coincide with the normal to the specimen surface. In our work, the necessary implantation zone for the iron ion beam with an energy of 3.2 MeV is located at depths of 300–800 nm. The simulation of the hydrogen and helium ion paths in the material of the iron target in the energy range from 150 to 600 keV at the angle to the normal from 0° to 65° is performed. The range of energies and irradiation angles for the hydrogen and helium ions are determined for the implantation into the radiation-induced defect-formation zone.
Using the Geant4 software package, a numerical simulation of a neutron source of the time-offlight spectrometer GNEIS created on the basis of the SC-1000 synchrocyclotron with 1 GeV proton energy at ...the NRC Kurchatov Institute—PNPI (Gatchina) has been carried out. The influence of the structural features of the neutron source of the spectrometer on the spatial and energy distributions of neutrons has been studied. The intensity and spectral characteristics of the neutron flux in the range of 1–1000 MeV have been determined on the basis of the obtained information and detailed allowance for all elements of the neutron beam guide system. It is found that the best agreement between the experiment and calculation performed by means of Geant4 is observed when using the QGSP_INCLXX_HP model. In the neutron energy range of 1–200 MeV, the difference between the experimental and calculated shapes of the spectra is less than 25%.
The HIPr-1 (Heavy-Ion Prototype) beam transport channel was designed for performing experiments to measure the energy losses in plasma, which was developed considering the results of the beam ...dynamics simulation.
A method for calculating electronic levels in compact superheavy nuclear quasimolecules based on solving the Dirac equation in spherical coordinates using a multipole expansion of a two-center ...potential is developed. It is shown that, for internuclear distances up to ∼100 fm, such a technique enables fast convergence, which allows one to calculate the electronic energy levels with an accuracy better than 10
−6
. Moreover, all the multipole moments can be calculated analytically. The critical distances between the similar colliding nuclei have been calculated in the range
Z
∼ 87–100 for bottom electronic levels: even 1σ
g
and odd 1σ
u
, respectively.
A mathematical model is presented that describes the effect of intense laser pulses of a rectangular shape on a two-layer cylindrical target. The fluxes of the intrinsic plasma radiation for seven ...spectral ranges are calculated as a function of the radial target coordinate. Spatial distributions of the total flux of the plasma radiation are presented.
A new accelerator complex, Nuclotron based Ion Collider fAcility (NICA), is being created on the basis of the Joint Institute for Nuclear Research (JINR, Dubna, Russia) to study the properties of ...dense baryonic matter. It is planned to use superconducting sections as part of the accelerator injector NICA. The first of these sections will consist of quarter-wave coaxial resonators, working at a frequency of 162MHz with β = 0.121,2.For effective operation of such resonators, it is necessary to develop a reliable RF power input device. This article describes the power input design, based on a coaxial waveguide. Issues of thermal reliability of the device are considered, and electrodynamic characteristics are presented.
The OKA detector is described, and recently published results of experimental searches for a heavy neutrino and investigations of the
K
e
3
-decay form factors are reported. Incident-beam ...characteristics, the detector configuration and its major subsystems, and triggering conditions are discussed. Physical motivations for these experimental studies are provided, and the event-selection procedures are briefly described.
