Excitation of the 103Rh, sup(107,109)Ag and 197Au nuclei induced by the positron annihilation on bound electrons of atom

Excitation of the nuclei 103Rh, sup(107, 109)Ag, and 197Au in electron annihilation on atomic bound electrons has been for the first time experimentally observed. Nuclear excitation was identified by detecting the Roentgen radiation arising from the electron conversion of the isomer states of 103Rb (Tsub(1/2)=56.1 min), 107Ag (Tsub(1/2)=44.3 s), 109Ag (Tsub(1/2)=39.8 s), and 19αu (Tsub(1/2)=7.7 s). The integral σsub(eff), resonance σsub(res), and nonresonance σsub(nonres) excitation cross sections are found for excitation of the considered nuclei caused by the positron annihilation. The results are discussed and compared to the theory