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%.
Abstract
Method for production of alpha emitter
149
Tb by irradiation of
151
Eu with 70 MeV
3
He nuclei is proposed. For the first time, the cross sections for the formation of isotopes
...149,150,151,152
Tb were measured experimentally using a stack foil technique in the
3
He particles energy range 70 → 12 MeV. The thick target yield of
149
Tb is 39 MBq/μAh, or 230 MBq/μA
149
Tb at saturation. The optimal energy range from the point of view of radioisotopic purity is 70 → 40 MeV. At these conditions about 150 MBq/μA
149
Tb can be produced in 8 hours irradiation, which is sufficient for therapeutic applications. The main impurities are
150
Tb (~100% in activity) and
151
Tb (~30% in activity). The proposed method surpasses its counterparts by the high content of the target isotope in the natural mixture and the simplicity of the radiochemical separation of
149
Tb from the bulk target material.
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.
155Tb (T1/2 = 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 155Tb 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 155Tb via formation of 155Dy (T1/2 = 9.9 h), which can be implemented using medium energy alpha particles beam.
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 155Tb was isolated by the same method.
The cross sections for the formation of 159Gd, 153-156Tb, and 155,157Dy 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/μAh, which makes it possible to obtain 1 GBq 155Tb as a result of 12-hour irradiation with a beam current of 50 μA. 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 153Tb (T1/2 = 2.34 d; <5.4% of 155Tb activity).
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 155Tb 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 γ-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 157Tb (T1/2 = 71 a, the only γ-line 54.5 keV Iγ = 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 155Gd or 156Gd nuclide as a target will help not only reduce the amount of impurities but also increase the yield of 155Tb.
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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
Rh with parent nuclide of
Ru (
min and
d respectively) is to be noted. This work provides new experimental data of cumulative yield of
Ru radionuclide for
He-,
He-, proton- and deuteron-induced reactions on ‘‘thick’’ ThO
targets. Data shows that acquired activity of
Ru is sufficient for creation of
Ru/
Rh generator.
The production cross sections of
163,165,166,167,168
Tm in alpha-particle induced reactions on
165
Ho were measured in 27–60 MeV energy range using the stacked-foil activation technique. The thick ...target yield of the medical isotope
167
Tm is 2.22 MBq/µAh. The radioisotope
165
Tm that can be used in the generator system to obtain
165
Er 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
165
Tm and
165
Er production were compared. The reaction
165
Ho(α,4n)
165
Tm →
165
Er was considered as a potential method for the production of
165
Er.
The excitation functions of nuclear reactions natBa(α,xn)132, 133m, 134, 135, 137m,g, 139, 141Ce, natBa(α,x)135, 140La and natBa(α,x)131, 133m, 135mBa were measured for the first time in the energy ...range of 60 → 20 MeV using stack foil technique combined with γ-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 production of medical radioisotopes 134Ce and 135La is discussed.
The cross sections for the formation of 160Er, 161Er, 162mHo, 157Dy in nuclear reactions natDy(α,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/µAh. The natDy(α,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/µAh, which is significantly less than those of the reactions induced by protons and deuterons.
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.
—
The influence of proton irradiation on the structure of Nb
3
Sn superconducting materials has been investigated. The irradiation to different proton doses was performed on a cyclotron at the ...National Research Centre “Kurchatov Institute” (NRC KI). The Nb
3
Sn samples were placed successively pairwise on the beam axis to obtain different degrees of radiation-induced damage at a specified dose. X-ray diffraction (XRD) analysis of irradiated and unirradiated samples was carried out on a synchrotron radiation source at the NRC KI. The results of studies revealed that the diffraction peaks broaden and become weaker with an increase in the concentration of radiation-induced defects. The phase compositions of the samples and dynamics of changes in the found NbO phase under irradiation have been investigated. The change in the lattice period for the irradiated samples is studied. It is shown that the lattice period increases with an increase in concentration of radiation-induced defects.
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