Measurement of Cumulative Yield of the $${}^{{103}}$$ Ru Radionuclide for $${}^{{4}}$$ He-, $${}^{{3}}$$ He-, Proton- and Deuteron-Induced Reactions on ThO $${}_{{2}}$$ Targets

Physics of Atomic Nuclei - Modular nanotransporters (MNTs) are promising technology for nuclear medicine of the present time which is based on an engineered polypeptide platform. Emitters of Auger...     

The Use of Synchrotron Radiation for Studying Superconducting Nb3Sn Samples Irradiated by Fast Particle Beams

Crystallography Reports - The influence of proton irradiation on the structure of Nb3Sn superconducting materials has been investigated. The irradiation to different proton doses was performed on a...     

Analysis of a tungsten surface irradiated by fast ions and deuterium plasma

The effects occurring on the surface of tungsten under irradiation with fast ions with an energy in the megaelectrolvolt range and with high fluxes of hydrogen (deuterium) plasma are considered. These effects are radiation damage of the surface layer of the material, its erosion and deuterium retention in it. Irradiation with helium ⁴He²⁺ (3.2–4.0 MeV) and carbon ¹²C³⁺ (10 MeV) ions is performed using a cyclotron at the National Research Center Kurchatov Institute. The thickness of the damaged layer is 3.5–6 μm. The irradiated samples are exposed to steady-state deuterium plasma using a LENTA linear plasma facility to reach a plasma ion fluence of 10²¹–10²² cm^?2. Tungsten erosion and modification of the structure of the damaged layer are analyzed at a plasma-ion energy of 250 eV. Deuterium retention in the damaged layer is studied by elastic recoil detection analysis. The deuterium concentration and its penetration depth into the material are measured. The data obtained for different kinds of fast ions used in the work are compared.     

Study of the impact of steady-state plasma on radiation-damaged tungsten

Experimental studies of tungsten (as a candidate plasma-facing material for a fusion reactor) whose properties will degrade as a result of its contact with near-wall plasma and irradiation with neutrons are performed. The effect of a high level of radiation damages (1–100 displacements per atom) on deuterium accumulation and erosion caused by tungsten irradiation with deuterium plasma was studied. Radiation damages are obtained as a result of the irradiation of tungsten samples with high-energy ions in an accelerator (He⁺², C⁺³, 4–10 MeV). Then the samples are exposed to steady-state deuterium plasma at the LENTA facility (National Research Centre Kurchatov Institute). The effects of the erosion of tungsten and accumulation of hydrogen isotopes in it are studied. Modification of the surface microstructure and radiation swelling is observed. The helium and deuterium concentrations were measured using the methods of nuclear elastic backscattering and elastic recoil detection analysis. An increased accumulation of deuterium in the damaged layer to a depth of about 5 μm is revealed.     

Radiation defect clustering in graphite studied by synchrotron radiation scattering

The formation of radiation defect clusters as interstitial dislocation loops in pyrographite irradiated by 20-MeV carbon ions in a cyclotron has been studied by means of synchrotron radiation scattering. The experimental data are interpreted in terms of the Krivoglaz model and the model of deformation domain formation by dislocation loops. Parameters of the pyrographite crystal lattice in the deformed state upon ion irradiation have been determined using experimental data on the shift and broadening of the Bragg peaks. The results of experiments and their theoretical analysis indicate that the phenomena of the crystal lattice densification (shrinkage) and the radiation-induced swelling (increase in volume) observed for graphite irradiated by fast neutrons in a nuclear reactor can be studied in model experiments on charged particle accelerators using irradiation of the samples with carbon ions at much lower doses and significantly shorter exposure times.     

Accumulation of deuterium in radiation-damaged tungsten

Experimental studies have been performed to determine the effect of high-level radiation damage on the accumulation of deuterium and erosion of tungsten samples exposed to deuterium plasma. Tungsten samples were exposed first to fast helium ions having an energy of 3–4 MeV (providing from one to ten displacements per atom) and then to deuterium plasma up to a dose of 10²⁵ ion/m². The effects of deformation and modification of the surface microstructure have been observed. The concentrations of helium and deuterium have been measured by the methods of elastic nuclear proton backscattering and nuclear recoil detection of helium ions. A high concentration of deuterium in the damaged layer of a tungsten sample has been measured, and helium has been detected in a layer ～5 μm thick. The proposed method shows promise for determining the lifetime of materials used in fusion reactors and measuring the concentration of tritium accumulated in these materials.     

On the possible separation of the phase enriched with Nb in superconducting intermetallic Nb<Subscript>3</Subscript>Sn irradiated with fast protons

The results of the study of magnetization and dynamic magnetic susceptibility are correlated with changes in the microstructure of superconducting intermetallic Nb₃Sn plates irradiated at the Kurchatov Institute cyclotron with fast protons with an energy of 12.8 MeV to a fluence of 1 · 10¹⁸ cm^?2. The dependence of the superconducting transition temperature on the total irradiation dose is determined. For one of the samples, the dynamic magnetic susceptibility exhibits several steps corresponding to superconducting transitions at different temperatures. It is assumed that a Nb-enriched phase is separated in the region of maximum radiation damages. A microstructural analysis shows the appearance of randomly oriented Nb-enriched regions from 0.1 to 0.5 μm in size.     

Application of cyclotrons in beam technologies

Some currently developed applications of cyclotrons (beam technologies) are discussed. They include new methods for producing radioisotopes for medical purposes and investigations into the radiation strength ofmaterials and the wear of units of variousmachines and devices bymeans of beams of radioactive nuclei.     

Measurement of Cross Sections for the Reactions $${}^{{232}}{\textrm{Th}}({{}^{3}}{\textrm{He}}{,p4n})^{{230}}$$ Pa, $${}^{{232}}{\textrm{Th}}({{}^{3}}{\textrm{He}}{,p2n})^{{232}}$$ Pa,and $${}^{{232}}{\textrm{Th}}({{}^{3}}{\textrm{He}}{,2p+pn})^{{233}}$$ Pa Induced by the Irradiation of a ThO $${}_{2}$$ Target with $${}^{3}$$ He Nuclei

Physics of Atomic Nuclei - The efficiency of employing a beam of intermediate-energy $${}^{3}$$ He particles for the production of the radionuclide $${}^{230}$$ Pa on natural-thorium targets, which...