Production cross sections of ytterbium and thulium radioisotopes in alpha-induced nuclear reactions on natural erbium

Activation cross sections of alpha-induced reactions on natural erbium were measured using a 50.9-MeV alpha-beam at the RIKEN AVF cyclotron. Well-established methods for the measurements, the stacked-foil activation technique and gamma-ray spectrometry, were used. Production cross sections of 166,169Yb and 165,166,167,168,170,173Tm were determined. This is the first measurement of the cross sections of 166,170Tm. The integral yield of the medical radionuclide 169Yb was derived from the measured excitation function