Two-stage excitation of nuclei in positron annihilation with atomic electrons

Two-stage nucleus excitation under positron annihilation by atomic electrons is considered. The cross section in the resonance for 115In equals to σR≅10-28 cm2 and the effective cross section σef≅10-32 cm2. The values obtained for σef should be considered as evaluations of the nucleus two-stage excitation effect value under positron annihilation, which can be specified in a more realistic calculation. 9 refs.; 1 fig