Experiment-based determination of the excitation function for the production of Ti44 in proton-irradiated vanadium samples
In this paper, the excitation function utilizing the nuclear reaction $^{\mathrm{nat}}\mathrm{V}(p,X)$ $^{44}\mathrm{Ti}$ was determined. The seven investigated metallic vanadium disks were proton irradiated within an energy range of 111--954 MeV between 1995 to 1996. The experiments' cross sections were validated using two independent measurements by combining $\ensuremath{\gamma}$ spectrometry with both a low-energy germanium detector and a high-purity germanium detector. The maximum cross section was observed for energies of 145 $\ifmmode\pm\else\textpm\fi{}$ 1.2 and 150.2 $\ifmmode\pm\else\textpm\fi{}$ 1.2 MeV with values of 803 $\ifmmode\pm\else\textpm\fi{}$ 28 and 805 $\ifmmode\pm\else\textpm\fi{}$ 27 $\ensuremath{\mu}\mathrm{b}$, respectively. In this regard, it was demonstrated that our data were in good agreement with the former, however, unpublished results which were investigated over a similar energy range. Thus, combined with these earlier measurements, a consistent data set for the $^{\mathrm{nat}}\mathrm{V}(p,X)$ $^{44}\mathrm{Ti}$ excitation function from 111 to 1350 MeV is provided. Model calculations using Li\`ege Intranuclear Cascade (INCL)/ABLA reproduce the shape of the excitation function correctly but overpredict the absolute values by factors of 2 to 3. Some considerations regarding this already earlier observed systematic overestimation of neutron-poor residues are given. The results will trigger new approaches in code development in order to improve the predictions.