An experimental complex was created at the NRC Kurchatov Institute for testing of structural materials developed for MSR. The complex makes it possible to implant helium and (or) hydrogen into material specimens at the U-150 cyclotron, simulating the result of long-term neutron exposure, to perform mechanical tests and microstructural studies before and after simulation exposure, and to test the compatibility of structural materials before and after exposure with fuel salt in non-isothermal dynamic conditions at temperatures up to 750°C with control of the melt redox potential. Preliminary tests with samples of nickel-molybdenum alloy KhN80MT demonstrated the efficiency of the proposed experimental technique. The concentration of helium nuclei in the alloy samples reaches 150 ppm for approximately 10 h of irradiation.

Тhe results of an experimental study of tungsten as a coating material for the divertor and the first wall of a thermonuclear tokamak reactor are presented. A method for modeling radiation damage of a material by thermonuclear neutrons based on the use of accelerated protons has been developed. A technique for irradiating tungsten samples (PLANSEE) with protons is developed at the cyclotron of the National Research Center Kurchatov Institute. During irradiation, protons with an energy of 3.7 MeV and the total fluence of 10 18 protons/cm 2 are used. The samples irradiated (0.05 dpa) are studied in deuterium plasma on the LENTA device. The results of irradiation and plasma exposure on the surface and the accumulation of deuterium in the irradiated material are presented.

The cumulative cross sections for 232 Th fission products in the energy range of 3 He nuclei of 39‒58 MeV are measured. The measurements are made using the activation technique and the foil stack technique. Eighteen cumulative cross sections for the 232 Th fission products by 3 He nuclei with half-lives from one day ( 112 Pd, T 1/2 = 21 h) to 64 days ( 95 Zr, T 1/2 = 64 d) are measured for the first time. Being fundamental constants, the results can supplement the existing libraries of nuclear data.

The excitation functions of nuclear reactions natBa(alpha,xn)132, 133m, 134, 135, 137m,g, 139, 141Ce, natBa(alpha,x)135, 140La and natBa(alpha,x)131, 133m, 135mBa were measured for the first time in the energy range of 60-+ 20 MeV using stack foil technique combined with gamma-ray spectrometry. A comparative analysis of the experimental results with TENDL-2021 data was carried out. The thick target yields of radioisotopes Ba, La, and Ce were calculated by integrating the values of the cross sections. The feasibility of practical use of the studied reactions for the pro-duction of medical radioisotopes 134Ce and 135La is discussed.

The 230U yield in the direct reactions 232Th(3He, 5n)230U and 232Th(4He, 6n)230U on thick ThO2 targets irradiated by 65 and 55 MeV nuclei 3,4He was measured and compared with calculations. The experimental yield of 230U in the reaction 232Th(3He, 5n)230U is approximately 10 times higher than the value computed using the constants from TENDL-2019. The experimental yield of 230U in the reaction 232Th(4He, 6n)230U the same, to within t5he limits of error, as the computed value. Comparing the experimental and computed yield in the reaction 232Th(4He, 6n)230U with the cross section obtained by the ALICA program (USA) showed that the computed cross section is incorrect and the prognoses for 230U production based on it are unsubstantiated. It is concluded that the reactions 232Th(3He, 5n)230U and 232Th(4He, 6n)230U are inefficient for 230U production in the U-150 cyclotron at the NRC Kurchatov Institute in amounts required for clinical applications.

Modular nanotransporters (MNTs) are promising technology for nuclear medicine of the present time which is based on an engineered polypeptide platform. Emitters of Auger electrons can be used in pair with MNTs as short-range cytotoxic agents, and among the most effective ones ^103m Rh with parent nuclide of ^103 Ru ( T_1/2=56.1 min and T_1/2=39.2 d respectively) is to be noted. This work provides new experimental data of cumulative yield of ^103 Ru radionuclide for ^4 He-, ^3 He-, proton- and deuteron-induced reactions on ‘‘thick’’ ThO _2 targets. Data shows that acquired activity of ^103 Ru is sufficient for creation of ^103 Ru/ ^103m Rh generator.

At present, the radioisotope U-230 is considered as one of the most promising alpha-emitters for application in immunotherapy. In order to refine nuclear data and to evaluate the efficiency of U-230 production, the cross sections for the reactions Th-232(He-4, p5n)Pa-230 -> U-230 and Th-232(He-4, 6n)U-230, as well as the cross sections for the accompanying reactions Th-232(He-4, p3n)Pa-232 and Th-232(He-4, 2pn + p2n)Pa-233, were measured for the first time in the range of energies of He-4 nuclei between 30 and 62 MeV. The activation technique was used to measure the reaction cross sections. The experimental cross sectionswere comparedwith data fromthe TENDL-2021 library. The results give grounds to conclude that the reactions Th-232(He-4, p5n)Pa-230 -> U-230 and Th-232(He-4, 6n)U-230 cannot ensure efficient production of U-230 at the U-150 cyclotron of National Research Center Kurchatov Institute. Therefore, they cannot be viewed as an alternative to proton- and deuteron-induced reactions producing U-230.

Separation technique of rhenium radioisotopes from a deuteron-irradiated tungsten target of natural isotopic composition has been developed. The irradiated tungsten powder was dissolved in a mixture of H 2 O 2 and NaOH, the solution was passed through a column filled with an extraction chromatographic sorbent TEVA Resin. Rhenium was eluted with 4 M nitric acid. The separation procedure takes approximately 3 h, the radiochemical yield of rhenium is more than 97%.

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 is used to obtain a $${}^{230}$$ U therapeutic $$\alpha$$ emitter was estimated. The cross section for the reaction $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p4n)^{230}$$ Pa and the cross sections for the accompanying reactions $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p2n)^{232}$$ Pa and $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},2p+pn)^{233}$$ Pa in the energy range from 39 to 58 MeV were measured. Experimental results were compared with theoretical data from TENDL-2019 library. The present experiment did not confirm a large cross-section values presented in TENDL-2019 library (up to 400 mb for the reaction $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p4n)^{230}$$ Pa). Therefore, this reaction can hardly be viewed as an alternative to proton- and deuteron-induced reactions for production of $${}^{230}$$ Pa. The cross sections for the reactions $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p2n)^{232}$$ Pa and $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},2p+pn)^{233}$$ Pa in TENDL-2019 also differ significantly from the experimental data.

The cross sections for the formation of 160Er, 161Er, 162mHo, 157Dy in nuclear reactions natDy(alpha,x) in the energy range 53 -> 20 MeV were measured by the stacked foils method. Most of the data were obtained for the first time. A comparison of the data with simulation results from the TENDL-2019 library is given. The 161Er yield on a thick target is 88.4 MBq/mu Ah. The natDy(alpha,x)161Er -> 161Ho route was studied for 161Ho production. The possibility to produce 161Ho in an amount sufficient for medical applications was shown. The main radioisotope impurity is 160m,gHo (in the amount of 3-6% in terms of activity). The thick target yield of 160Er is 2.16 MBq/mu Ah, which is significantly less than those of the reactions induced by protons and deuterons.

Abstract 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 is used to obtain a $${}^{230}$$ U therapeutic $$\alpha$$ emitter was estimated. The cross section for the reaction $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p4n)^{230}$$ Pa and the cross sections for the accompanying reactions $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p2n)^{232}$$ Pa and $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},2p+pn)^{233}$$ Pa in the energy range from 39 to 58 MeV were measured. Experimental results were compared with theoretical data from TENDL-2019 library. The present experiment did not confirm a large cross-section values presented in TENDL-2019 library (up to 400 mb for the reaction $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p4n)^{230}$$ Pa). Therefore, this reaction can hardly be viewed as an alternative to proton- and deuteron-induced reactions for production of $${}^{230}$$ Pa. The cross sections for the reactions $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},p2n)^{232}$$ Pa and $${}^{232}{\textrm{Th}}(^{3}{\textrm{He}},2p+pn)^{233}$$ Pa in TENDL-2019 also differ significantly from the experimental data.

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 is used to obtain a ^230 U therapeutic α emitter was estimated. The cross section for the reaction ^232Th(^3He,p4n)^230 Pa and the cross sections for the accompanying reactions ^232Th(^3He,p2n)^232 Pa and ^232Th(^3He,2p+pn)^233 Pa in the energy range from 39 to 58 MeV were measured. Experimental results were compared with theoretical data from TENDL-2019 library. The present experiment did not confirm a large cross-section values presented in TENDL-2019 library (up to 400 mb for the reaction ^232Th(^3He,p4n)^230 Pa). Therefore, this reaction can hardly be viewed as an alternative to proton- and deuteron-induced reactions for production of ^230 Pa. The cross sections for the reactions ^232Th(^3He,p2n)^232 Pa and ^232Th(^3He,2p+pn)^233 Pa in TENDL-2019 also differ significantly from the experimental data.

A laboratory setup has been developed for the isolation of rhenium radioisotopes from an irradiated tungsten target using extraction chromatography. The operation of the setup was tested using a target made of metallic tungsten of natural isotopic composition, irradiated with deuterons at the U-150 cyclotron of the Kurchatov Institute. The possibility of complete separation of rhenium from large amounts (hundreds of milligrams) of tungsten has been shown. During separation, rhenium is concentrated in a minimum volume (5 mL) of the final solution, providing a high specific activity required for further experiments to create a radiopharmaceutical.

A method for improving the production of the radioisotope 123I in proton cyclotrons, which makes it possible to increase its technological yield by 2–3 times, is reported. For this purpose, it is proposed to introduce hydrogen into a target with 124Xe, which makes it possible to extract from it the 123I formed over the irradiation time on decay of the accumulated 123Xe.

At present, the radioisotope ^230 U is considered as one of the most promising α -emitters for application in immunotherapy. In order to refine nuclear data and to evaluate the efficiency of ^230 U production, the cross sections for the reactions ^232 Th( ^4 He, p5n ) ^230Pa→^230 U and ^232 Th( ^4 He, 6n ) ^230 U, as well as the cross sections for the accompanying reactions ^232 Th( ^4 He, p3n ) ^232 Pa and ^232 Th( ^4 He, 2pn+p2n ) ^233 Pa, were measured for the first time in the range of energies of ^4 He nuclei between 30 and 62 MeV. The activation technique was used to measure the reaction cross sections. The experimental cross sections were compared with data from the TENDL-2021 library. The results give grounds to conclude that the reactions ^232 Th( ^4 He, p5n ) ^230Pa→^230 U and ^232 Th( ^4 He, 6n ) ^230 U cannot ensure efficient production of ^230 U at the U-150 cyclotron of National Research Center Kurchatov Institute. Therefore, they cannot be viewed as an alternative to proton- and deuteron-induced reactions producing ^230 U.

The production cross sections of 163,165,166,167,168Tm in alpha-particle induced reactions on 165Ho were measured in 27–60 MeV energy range using the stacked-foil activation technique. The thick target yield of the medical isotope 167Tm is 2.22 MBq/µAh. The radioisotope 165Tm that can be used in the generator system to obtain 165Er is also produced. The measured excitation functions were compared with the data from TENDL-2019 and TENDL-2021 libraries and the previous experimental values. Various methods of 165Tm and 165Er production were compared. The reaction 165Ho(α,4n)165Tm → 165Er was considered as a potential method for the production of 165Er.

Introduction: Tb-155 (T-1/2 = 5.32 d) is considered both as a promising Auger electron emitter and as a diagnostic pair for other therapeutic terbium radionuclides. Despite several methods for its production proposed, it remains scarcely available. Most of the methods using low-energy protons and deuterons beams result in a high content of radionuclidic impurities. High purity Tb-155 can be obtained using high-energy proton beams combined with online mass separation of products, but the method remains inaccessible to most potential consumers. We have proposed an indirect method for the production of Tb-155 via formation of Dy-155 (T1/2 = 9.9 h), which can be implemented using medium energy alpha particles beam. Methods: Gadolinium oxide targets of natural isotopic composition were irradiated by 60 MeV alpha particles beam on a U-150 cyclotron of the National Research Center "Kurchatov Institute ". The cross sections of nuclear reactions were measured by the stack foil technique, detecting the gamma radiation of the activation products. Gd, Tb, and Dy were separated by extraction chromatography using the LN Resin sorbent in nitric media. The isolated dysprosium fraction was stored for a day, and the formed Tb-155 was isolated by the same method. Results: The cross sections for the formation of Gd-159, Tb153-156, and Dy-155,Dy-157 under irradiation by alpha particles of a gadolinium target of natural isotopic composition in the energy range 20-60 MeV have been measured. The 155Dy yield on a thick target at 60 MeV was 35 MBq/mu Ah, which makes it possible to obtain 1 GBq Tb-155 as a result of 12-hour irradiation with a beam current of 50 mu A. Extraction chromatography on LN Resin sorbent in nitric enabled quick and efficient separation of Gd, Tb, and Dy. The radiochemical yield of Dy was 95%, for Tb > 95%. The main radionuclidic impurity is Tb-153 (T1/2 = 2.34 d; < 5.4% of 155Tb activity). Conclusions: The developed method allows the production of therapeutic amounts of 155Tb with acceptable radionuclidic purity without the need for isotopically enriched materials. The amount of Tb-155 is sufficient for its use in Auger therapy, as well as for preclinical studies of the suitability of SPECT preparations in laboratory animals. Nevertheless, to obtain higher activities, a longer irradiation time and a higher projectile current are proposed. The 153Tb radionuclide present in the final preparation has a shorter half-life than the target radionuclide, and its hard gamma-lines have a probability of emission of less than 1%, from which it can be concluded that the negative effect will not be significant. However, a product of this purity and type of contamination requires additional testing for toxicity in living organisms. The final sample also includes a certain amount of Tb-157 (T1/2 = 71 a, the only gamma-line 54.5 keV I gamma = 0.0084%), which will complicate the labeling conditions. Thus, more research is needed in the labeling area. It should be noted that the use of gadolinium enriched in the Gd-155 or 156Gd nuclide as a target will help not only reduce the amount of impurities but also increase the yield of 155Tb. (c) 2021 Elsevier Inc. All rights reserved.