  Natural silver targets have been irradiated by using a 50 MeV alpha-particle
beam in order to measure the activation cross sections of radioisotopes in the
40-50 MeV energy range. Among the radio-products there are medically important
isotopes such as $^{110m}$In and $^{111}$In. For optimizing the production of
these radioisotopes and regarding their purity and specific activity the cross
section data for every produced radioisotope are important. New data are
measured in this energy range and the results of some previous measurements
have been confirmed. Physical yield curves have been calculated by using the
new cross section data completed with the results from the literature.
