The effects of nuclear level density model and alpha optical model potential to the excitation functions of novel therapeutic radionuclides

In this study, the theoretical cross sections of 209Bi(α,2n)211At, 65Cu(α,n)68Ga, 100Ru(α,n)103Pd, and 121Sb(α,n)124I are calculated using TALYS 1.96, incorporating the effects of the alpha optical model potential and nuclear level density models. The validation process involves comparing the calculated cross sections with experimental data and utilizing statistical deviation factors. This comparison allows us to determine the optimal combination of nuclear model parameters for each reaction. The result shows that theoretical calculations which utilized semi microscopic level density models and alpha OMP managed to describe the excitation functions close to the experimental data. The comparison of nuclear model calculations with experimental data plays a crucial role in ensuring the reliability of the data, making it an essential aspect of modern evaluation procedures.

Excitation functions for 209Bi reactions induced by threshold to 50 MeV energy alpha particles

Excitation functions for ²⁰⁹Bi(α,2n)²¹¹At, ²⁰⁹Bi(α,3n)²¹⁰At and ²⁰⁹Bi(α,4n)²⁰⁹At reactions were calculated using TALYS-1.95 nuclear code from threshold to 50 MeV by invoking suitable options for level densities, nucleon-nucleus optical model potentials and alpha optical model potentials. Statistical factors were used to verify the quality of matching between theoretical model calculations and the experimental data from the EXFOR database. The TTY of ²¹¹At calculated using the excitation function of ²⁰⁹Bi(a,2n)²¹¹At reaction is compared with existing experimental studies from literature The results of the present study are important for the validation of nuclear model approaches with increased predictive power for ²⁰⁹Bi(α,xn) reactions for the production of ²¹¹At.

Pairing of thorium with selected primary target materials in tandem configurations: Co-production of 225Ac/213Bi and 230U/226Th generators with a 70 MeV H- cyclotron

Several radionuclide production facilities based on a new generation of high-current, 70 MeV H^- cyclotrons have been established in recent years and a number of new facilities are either under construction or being planned. In this study, the feasibility to produce ²²⁵Ac/²¹³Bi and ²³⁰U/²²⁶Th generators via Th + p reactions at such a facility has been investigated. From the perspective of production yields, it has been found useful to compare the relevant reactions on thorium with those on other targets regularly employed in this energy region, in particular the ^natMg(p,x)²²Na, ^natGa(p,x)⁶⁸Ge, and ^natRb(p,x)⁸²Sr reactions that have been exploited with 66 MeV proton beams at iThemba LABS for many years. Therefore, various tandem configurations of thorium with magnesium, gallium and rubidium are discussed based on the relevant nuclear data. In a few cases, the available data were judged to be insufficient in this energy region. New experimental cross sections are presented for ²²⁵Ac, ²²⁵Ra, and ²³⁰Pa in Th + p reactions as well as ^22,24Na in ^natMg + p reactions. Integral yields have been derived for those radionuclides of main interest. Production yields expected from extended 70 MeV proton bombardments, on selected tandem-target configurations, are presented for ²²Na, ⁶⁸Ge, ⁸²Sr, ²²⁵Ac, and ²³⁰Pa. It is concluded that ²²⁵Ac/²¹³Bi generators can, in principle, be added to a production programme based at a 70 MeV H^- cyclotron facility as the production rate is of similar magnitude to those of other well-established radionuclides in this energy region. Also, radio-contaminant levels for ²²⁵Ac are similar to those found in higher proton-energy windows. The scope for ²³⁰U/²²⁶Th generators, via bulk production of the precursor ²³⁰Pa, seems to be more limited due to a lower yield but can nevertheless be produced in clinically relevant quantities.

Analysis of neutron induced (n,γ) and (n,2n) reactions on 232Th from reaction threshold to 20 MeV

Excitation functions for ²³²Th(n,γ) and ²³²Th(n,2n) reactions from reaction threshold to 20 MeV were calculated using TALYS-1.9 nuclear code by invoking suitable options for the level densities, optical model potentials, pre-equilibrium effects and γ-ray strength functions. In earlier studies, theoretical plots for ²³²Th(n,γ) and ²³²Th(n,2n) reaction cross-sections were obtained by using EMPIRE 3.2 and TALYS 1.9 codes with default parameters, however none of the reported plots could match with the corresponding experimental cross-sections reported in EXFOR data particularly between 14-20 MeV. The results of the present study reveal that by using a combination of specific input parameters in TALYS 1.9 code, the theoretical evaluation of the cross sections favour a higher pre-equilibrium rate for the harder spectrum. Moreover the estimated cross-sections match fairly well with the corresponding experimental data (EXFOR database) as well as with the evaluated data files (ENDF/VII.0, JENDL-4.0). The results of the present study are important for the validation of nuclear model approaches with increased predictive power for (n,xn) cross-sections and particularly for the application of thorium based fuel in Accelerator-Driven Sub-critical System.

Excitation functions of proton- and deuteron-induced nuclear reactions on natural iridium for the production of 191Pt

We studied the excitation functions of residual radionuclides produced via proton and deuteron bombardment on natural iridium in the energy ranges of 30-15 MeV and 50-15 MeV, respectively. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for ^{189, 191}Pt and ^{189, 190g, 192g, 194g}Ir radionuclide production. Theoretical thick target yields were estimated to be 172 MBq/µA h and 192 MBq/µA h via the ¹⁹³Ir(p,3n)¹⁹¹Pt reaction at 29.6-17.5 MeV and the ¹⁹³Ir(d,4n)¹⁹¹Pt reaction at 40.3-23.8 MeV, respectively. The feasibility of ¹⁹¹Pt production from an iridium target was discussed, and compared with previously reported methods for the production of ¹⁹¹Pt.

Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50MeV

The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications.