Prediction of 67Ga production using the Monte Carlo code MCNPX

Evaluation of nuclear reaction cross sections for optimization of production of the non-standard positron emitting radionuclide 90Nb using proton induced reactions on Zr target

Niobium-90 radionuclide is one of the promising candidates for the positron emission tomography (PET) technique. In this study, ⁹⁰Nb excitation functions via ⁹⁰Zr(p,n) and ^natZr(p,xn) reactions were computed using the TALYS-1.95 code based on phenomenological and microscopic level density models. The MCNPX simulation code was used for each case. Moreover, the target thicknesses were obtained using the SRIM-2013 code and the theoretical and simulation-based production yields of the ⁹⁰Nb were evaluated. The experimental production yield amounts of about 72.68 and 126.7 (both in MBq/μAh) for ⁹⁰Zr(p,n) and ^natZr(p,xn) reactions in the corresponding optimal energy windows were attained by our experiments respectively.

FLUKA simulation yields in a comparison with theoretical and experimental yields relevant to 89Zr produced in the 89Y(p,n) reaction

The high importance of zirconium-89 (T1/2 = 78.41 h) is related to its applications in medical imaging. It can be produced at low-energy cyclotrons by the reaction 89Y(p,n)89Zr. There exist several publications on its production at low and intermediate energies but there is discrepancy with simulated data. In this study we considered the experimental parameters for four different types of yttrium foil targets reported in literature. The experimental parameters considered were the target geometry, beam profile, and angle of the target relative to the beam during irradiation. The Monte-Carlo code FLUKA was used to calculate production yields. The resulting values obtained by FLUKA from pencil beam or spread energy beam were compared to the theoretical yields obtained from the excitation function and the experimental ones. The FLUKA prediction for 89Z-yield reached ≈50 MBq/μA · h which agrees to a high extent with experimental and theoretical yields reported for the different targets.

Experimental study and simulation of 63Zn production via proton induce reaction

The ⁶³Zn was produced by16.8 MeV proton irradiation of natural copper. Thick target yield for ⁶³Zn in the energy range of 16.8 →12.2 MeV was 2.47 ± 0.12 GBq/μA.h. Reasonable agreement between achieved experimental data and theoretical value of thick target yield for ⁶³Zn was observed. A simple separation procedure of ⁶³Zn from copper target was developed using cation exchange chromatography. About 88 ± 5% of the loaded activity was recovered. The performance of FLUKA to reproduce experimental data of thick target yield of ⁶³Zn is validated. The achieved results from this code were compared with the corresponding experimental data. This comparison demonstrated that FLUKA provides a suitable tool for the simulation of radionuclide production using proton irradiation.

Validating production of PET radionuclides in solid and liquid targets: Comparing Geant4 predictions with FLUKA and measurements

The Monte Carlo toolkit Geant4 is used to simulate the production of a number of positron emitting radionuclides: ¹³N, ¹⁸F, ⁴⁴Sc, ⁵²Mn, ⁵⁵Co ⁶¹Cu, ⁶⁸Ga, ⁸⁶Y, ⁸⁹Zr and ⁹⁴Tc, which have been produced using a 13MeV medical cyclotron. The results are compared to previous simulations with the Monte Carlo code FLUKA and experimental measurements. The comparison shows variable degrees of agreement for different isotopes. The mean absolute deviation of Monte Carlo results from experiments was 1.4±1.6 for FLUKA and 0.7±0.5 for Geant4 using TENDL cross sections with QGSP-BIC-AllHP physics. Both agree well within the large error, which is due to the uncertainties present in both experimentally determined and theoretical reaction cross sections. Overall, Geant4 has been confirmed as a tool to simulate radionuclide production at low proton energy.

Modeling and experimental data of zirconium-89 production yield

The radionuclide zirconium-89 can be employed for the positron emission tomography (PET). In this study ⁸⁹Zr excitation function via ⁸⁹Y(p,n)⁸⁹Zr reaction was calculated by the TALYS-1.8 code based on microscopic level density model. The formation of ⁸⁹Zr was simulated using the Monte Carlo simulation code MCNPX to calculate the integral yield in the ⁸⁹Y target body for threshold up to 40MeV incident-proton energy. The target thickness was based on calculation of the stopping power using the SRIM-2013 code matched to any incident-proton energy. The production yield of the ⁸⁹Zr simulated with the Monte Carlo method for the ⁸⁹Y(p,n)⁸⁹Zr, ⁸⁹Y(d,2n)⁸⁹Zr, ^natSr(α,xn)⁸⁹Zr and ^natZr(p,pxn)⁸⁹Zr reactions and the results were in good agreement with published experimental results for the optimum energy range. An experimental yield of 53.1MB/µA for the 15MeV proton-induced on Y₂O₃ powder as a disk-target obtained for 1h irradiation at the AMIRS cyclotron.

Theoretical assessment and targeted modeling of TiO2 in reactor towards the scandium radioisotopes estimation

⁴⁷Sc radioisotope with beta particle emission can be used for targeted radionuclide therapy in nuclear medicine and can be produced by nuclear reactor (with high activities) and accelerator. In this work, the specific activity of ⁴⁷Sc with the isotopic impurities produced through irradiating the enriched ⁴⁷Tio₂ and natural TiO₂ targets have been calculated by the MCNPX-2.6 and the TALYS-1.8 codes and also theoretical approach in a fast neutron flux 3×10¹³ncm^-2s^-1 in the reactor. In addition, the cross sections of ⁴⁶Ti(n,p)⁴⁶Sc reaction have been interpolated in the 1-10MeV energy range and compared with the corresponding experimental data, as well. Moreover, the average cross sections of ⁴⁶Ti(n,p)⁴⁶Sc, ⁴⁷Ti(n,p)⁴⁷Sc and ⁴⁸Ti(n,p)⁴⁸Sc reactions were reproduced. Acceptable agreement between the experimental data and calculated results confirms the ability of the used methods to design and predict the production process in reactor.

Assessment and estimation of 67Cu production yield via deuteron induced reactions on natZn and 70Zn

⁶⁷Cu radioisotope is a beta particle-emitting nuclide used in radioimmunotherapy (RIT) as well as for imaging, tracer kinetic studies and dosimetry. ⁶⁷Cu can be produced by bombarding ^natZn with deuterons. In this study, the physical yields of ⁶⁷Cu via ^natZn(d,x)⁶⁷Cu reaction channel as well as via subreactions of ⁶⁸Zn(d,2pn)⁶⁷Cu, ⁶⁷Zn(d,2p)⁶⁷Cu, ⁷⁰Zn(d,2p3n)⁶⁷Cu, ⁶⁸Zn(d,x)⁶⁷Ni(T_1/2=21s)→⁶⁷Cu and ⁷⁰Zn(d,x)⁶⁷Ni(T_1/2=21s)→⁶⁷Cu in the ^natZn target have been calculated by using the MCNPX-2.6, TALYS-1.8 and SRIM codes. Also, the total cross sections for production of ⁶⁷Cu from ^natZn(d,x)⁶⁷Cu reaction channel in the energy range of 15-45MeV have been estimated by TALYS code. The best reaction to produce ⁶⁷Cu radionuclide in a carrier free form was chosen with deuteron energy around 30MeV on ⁷⁰Zn thick target. Good agreement between the calculated results and the experimental values shows that the employed methods can be used for prediction and production estimation in cyclotron.