Activation cross-sections of proton induced reactions on $^{nat}$Hf in the 38 to 65 MeV energy range. Production of $^{172}$Lu and of $^{169}$Yb

In the frame of a systematical study of light ion induced nuclear reactions on hafnium, activation cross sections for proton induced reactions were investigated. Excitation functions were measured in the 38 to 65 MeV energy range for the $^{nat}$Hf(p,xn)$^{180g,177,176,175,173}$Ta, $^{nat}$Hf(p,x)$^{180m,179m,175,173,172,171}$Hf, $^{177g,173,172,171,170,169}$Lu and $^{nat}$Hf(p,x)$^{169}$Yb reactions by using the activation method, combining stacked foil irradiation and off line gamma ray spectroscopy. The experimental results are compared with earlier results in the overlapping energy range, and with the theoretical predictions of the ALICE IPPE and EMPIRE theoretical codes and of the TALYS code reported in the TENDL2015 and TENDL2017 libraries. The production routes of $^{172}$Lu (and its parent $^{172}$Hf) and of $^{169Y}$b are reviewed.