No Arabic abstract
The production cross sections of $^{68,69}$Ge and $^{66,67}$Ga by alpha-induced reactions on $^{nat}$Zn have been measured using the stacked-foil activation method and off-line gamma-ray spectrometry from their threshold energies to 50.7 MeV. The derived cross sections were compared with the previous experimental data and the calculated values in the TENLD-2017 library. Our result shows a slightly larger amplitude than the previous data at the peak, though the peak energy is consistent with them.
In the frame of a systematic study of charged particle production routes of medically relevant radionuclei, the excitation function for indirect production of $^{178m}$Ta through $^{nat}$Hf($alpha$,xn)$^{178}$W-$^{178m}$Ta nuclear reaction was measured for the first time up to 40 MeV. In parallel, the side reactions $^{nat}$Hf($alpha$,x)$^{179,177,176,175}$W, $^{183,182,178g,177,176,175}$Ta, $^{179m,177m,175}$Hf were also assessed. Stacked foil irradiation technique and $gamma$-ray spectrometry were used. New experimental cross section data for the $^{nat}$Ta(d,xn)$^{178}$W reaction are also reported up to 40 MeV. The measured excitation functions are compared with the results of the ALICE-IPPE, and EMPIRE nuclear reaction model codes and with the TALYS 1.4 based data in the TENDL-2013 library. The thick target yields were deduced and compared with yields of other charged particle ((p,4n), (d,5n) and ($^3$He,x)) production routes for $^{178}$W.
Background: alpha-nucleus potentials play an essential role for the calculation of alpha-induced reaction cross sections at low energies in the statistical model... Purpose: The present work studies the total reaction cross section sigma_reac of alpha-induced reactions at low energies which can be determined from the elastic scattering angular distribution or from the sum over the cross sections of all open non-elastic channels. Method: Elastic and inelastic 64Zn(a,a)64Zn angular distributions were measured at two energies around the Coulomb barrier at 12.1 MeV and 16.1 MeV. Reaction cross sections of the (a,g), (a,n), and (a,p) reactions were measured at the same energies using the activation technique. The contributions of missing non-elastic channels were estimated from statistical model calculations. Results: The total reaction cross sections from elastic scattering and from the sum of the cross sections over all open non-elastic channels agree well within the uncertainties. This finding confirms the consistency of the experimental data. At the higher energy of 16.1 MeV, the predicted significant contribution of compound-inelastic scattering to the total reaction cross section is confirmed experimentally. As a by-product it is found that most recent global alpha-nucleus potentials are able to describe the reaction cross sections for 64Zn around the Coulomb barrier. Conclusions: Total reaction cross sections of alpha-induced reactions can be well determined from elastic scattering angular distributions. The present study proves experimentally that the total cross section from elastic scattering is identical to the sum of non-elastic reaction cross sections. Thus, the statistical model can reliably be used to distribute the total reaction cross section among the different open channels.
New data for the $^mbox{nat}$V(p,x) reactions have been measured in the range 26-70 MeV, with production of the nuclides $^{47}$Sc, $^{43}$Sc, $^{44m}$Sc, $^{44g}$Sc, $^{46}$Sc, $^{48}$Sc, $^{42}$K, $^{43}$K, $^{48}$V, $^{48}$Cr, $^{49}$Cr, and $^{51}$Cr. The focus is on the production of $^{47}$Sc, a $beta^-$-emitter suitable for innovative radiotheranostic applications in nuclear medicine. The measured cross sections for this radionuclide and its contaminants are compared with the theoretical excitation functions calculated with the TALYS code. In view of novel radiopharmaceutical applications, it is essential to accurately describe these cross-sections for the evaluation of yields, purities, and dose releases. Hence, we optimize the level-density parameters of the microscopic models in the TALYS code to obtain the best possible descriptions of the new data. We consider different irradiation conditions to estimate the production yields from the cross sections determined in this work.
[Background] Alpha-nucleus optical potentials are basic ingredients of statistical model calculations used in nucleosynthesis simulations. While the nucleon+nucleus optical potential is fairly well known, for the alpha+nucleus optical potential several different parameter sets exist and large deviations, reaching sometimes even an order of magnitude, are found between the cross section predictions calculated using different parameter sets. [Purpose] A measurement of the radiative alpha-capture and the alpha-induced reaction cross sections on the nucleus 115In at low energies allows a stringent test of statistical model predictions. Since experimental data is scarce in this mass region, this measurement can be an important input to test the global applicability of alpha+nucleus optical model potentials and further ingredients of the statistical model. [Methods] The reaction cross sections were measured by means of the activation method. The produced activities were determined by off-line detection of the gamma-rays and characteristic x-rays emitted during the electron capture decay of the produced Sb isotopes. The 115In(alpha,gamma)119Sb and 115In(alpha,n)118Sbm reaction cross sections were measured between Ec.m. = 8.83 MeV - 15.58 MeV, and the 115In(alpha,n)118Sbg reaction was studied between Ec.m. = 11.10 MeV - 15.58 MeV. The theoretical analysis was performed within the statistical model.
The 106Cd(alpha,gamma)110Sn reaction cross section has been measured in the energy range of the Gamow window for the astrophysical p-process scenario. The cross sections for 106Cd(alpha,n)109Sn and for 106Cd(alpha,p)109In below the (alpha,n) threshold have also been determined. The results are compared with predictions of the statistical model code NON-SMOKER using different input parameters. The comparison shows that a discrepancy for 106Cd(alpha,gamma)110Sn when using the standard optical potentials can be removed with a different alpha+106Cd potential. Some astrophysical implications are discussed.