Experimental study of the 165Ho(p,n) nuclear reaction for production of the therapeutic radioisotope 165Er

The 10.3 h half life radionuclide 165Er, decaying by electron capture to stable 165Ho, is an excellent candidate for Auger-electron therapy. In the frame of a systematic study of charged particle production routes of 165Er, the excitation function of the 165Ho(p,n)165Er reaction was measured up to 35 MeV by using a stacked foil irradiation technique and X-ray spectroscopy. The measured excitation function shows a significant energy shift when compared to the only experimental dataset measured earlier and an acceptable agreement with the results of different nuclear reaction model codes. The thick target yields calculated from the excitation function at typical energies available at small cyclotrons (Ep = 11 MeV and Ep = 15 MeV) are 41 MBq/μAh = 11 GBq/C and 75 MBq/μAh = 21 GBq/C, respectively.