Four terbium isotopes 149,152,155,161Tb emitting various types of radiation can be used for both diagnostics and therapy. 152Tb emits positrons and is ideal for PET. 155Tb is considered a promising ...Auger emitter and a diagnostic pair for other terbium therapeutic isotopes. Several methods for the production of 155Tb using charged particle accelerators have been proposed, but they all have significant limitations. The restricted availability of this isotope hinders its medical applications. We have proposed a new method for production of 155Tb, irradiating enriched 155Gd by alpha particles. The possibility of simultaneous production of two isotopes of terbium, 152,155Tb, was also studied for more efficient cyclotron beam use.
Irradiation of 155Gd enriched targets and 155Gd / 151Eu tandem target with alpha-particles with an energy of 54 MeV was carried out at the U-150 cyclotron at the NRC “Kurchatov Institute”. The cross sections of nuclear reactions on enr-155Gd were measured by the stack foil technique, detecting the gamma-radiation of the activation products. The separation of rare earth elements was performed by extraction chromatography with the LN Resin. 155Tb was produced via 155Dy decay.
The cross sections for the 155,156Tb and 155,157Dy production were measured by the irradiation of a gadolinium target enriched with the 155Gd isotope with alpha-particles in an energy range of 54 → 33 MeV. The yield of 155Dy on a thick target at 54 MeV was 130 MBq/μAh, which makes it possible to obtain 1 GBq of 155Tb in 11 h-irradiation with 20 μA beam current. The possibility of simultaneous production of 152,155Tb by irradiation of 155Gd and 151Eu tandem target with medium-energy alpha-particles is implemented. Optimal irradiation energy ranges of alpha -particles as 54 → 42 MeV for 155Tb and 42 → 34 MeV for 152Tb were suggested. Product activity and radionuclidic purity were calculated.
New nuclear data relevant to the production of 155Tb were obtained. The proposed tandem target approach allows for increasing the availability of medical radioisotopes 152,155Tb.
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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 analysis of the use of α-particle beams for the production of radionuclides is carried out. The advantages and disadvantages of this approach in comparison with traditional proton and deuteron ...beams are considered. It is shown that in some cases accelerated helium-ion beams are the only way to produce important medical radionuclides, and in some cases they are competitive with hydrogen-ion beams.
Two rhenium isotopes (
186
Re and
188
Re) are of interest for nuclear medicine. The multiplicity of oxidation states and varying coordination chemistry of rhenium provide opportunities for the ...synthesis of various bioconjugates, including those based on nanosized carriers (liposomes, dendrimers, and inorganic nanoparticles). This review analyzes nuclear reactions that lead to the formation of rhenium isotopes and methods of their isolation from targets, as well as different variants of the application of rhenium in nuclear medicine.
The production possibility of 161Tb and 155Tb by irradiating of natural dysprosium with gamma rays obtained by decelerating an electron beam with an energy of 55 MeV has been demonstrated ...experimentally. The yield of 161Tb was 14.4 × 103 Bq × μA−1 × h−1 × cm2 × gDy2O3−1. Simultaneously, upon irradiation, 155Dy is formed with the yield of 25 × 103 Bq × μA−1 × h−1 × cm2 × gDy2O3−1, which leads to the formation of 1.6 × 103 Bq × μA−1 × h−1 × cm2 × gDy2O3−1 of 155Tb. It has been shown that the isolation of terbium radioisotopes from tens of mg of dysprosium target can be achieved by extraction chromatography, and final separation yield was 39%. The impurity of 160Tb is 7.3% of the 161Tb activity at EOB.
•Production of 161Tb and 155Tb from natural dysprosium by photonuclear method.•Yield calculation of the nuclides 161Tb, 155Tb, 160,163Tb, 155,157Dy.•Isolation of terbium isotopes by extraction chromatography.•For the production of 161Tb the use of the target enriched with 162Dy will increase the radioisotopic purity of the product.
The cross sections for nuclear reactions natEr(α,x) were measured in the energy range 60 → 10 MeV using the stacked-foil technique. The experiments were carried out in a wider energy range in ...comparison with previous works. The results are consistent with other studies and modeling using TENDL-2019. The 167Tm yield was 5.4 MBq/μAh in the range 60 → 30 MeV, and the main long-lived impurity is 168Tm (0.78% in terms of activity). The 165Tm yield is 4.6 MBq/μAh (60 → 40 MeV). 169Yb is formed with a yield of 1.0 MBq/μAh in the energy range 60 → 20 MeV.
•Activation cross-sections of alpha-particle induced reactions were measured on natural erbium target.•Stacked-foil technique, activation method and gamma-spectroscopy were used.•Cross section for ytterbium (167,169Yb and thulium (165Tm, 166Tm, 167cumTm, 168Tm) were determined.•Production routs of 169Yb, 167Tm and 165Er were discussed.
The cross sections of the reactions
186
W(
4
He, p3n)
186
Re,
186
W(
4
He, pn)
188
Re, and
186
W(
4
He, p)
189
Re were measured by the activation method in the energy range of 4He nuclei 24–63 MeV. ...For all three reactions the cross sections in the TENDL-2019 nuclear data library differ from experiment by more than a factor of 2 in a wide energy range.
The production cross sections of .sup.163,165,166,167,168Tm in alpha-particle induced reactions on .sup.165Ho were measured in 27-60 MeV energy range using the stacked-foil activation technique. The ...thick target yield of the medical isotope .sup.167Tm is 2.22 MBq/microAh. The radioisotope .sup.165Tm that can be used in the generator system to obtain .sup.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 .sup.165Tm and .sup.165Er production were compared. The reaction .sup.165Ho(alpha,4n).sup.165Tm right arrow .sup.165Er was considered as a potential method for the production of .sup.165Er.
