Decay properties of ground-state and isomer of 103In

Abstract

The β-decay properties of ground-state and isomer of 103In were investigated by means of γ-ray spectroscopy. The half-lives of 103g In and 103m In were determined to be 60 ± 1 s and 34 ± 2 s, respectively. Out of 149 γ transitions ascribed to the decay of 103g In, 104 have been placed in a decay scheme including 55 excited states of 103g Cd. The main part of the resulting distribution of the Gamow-Teller strength B(GT) is associated with the feeding of 103Cd levels at excitation energies around 3 MeV. This observation can be interpreted as a sign of dominant feeding of three-quasiparticle states in 103Cd, which correspond to the 1+(πg 9/2 −1 , vg7/2)⊗πg9/2 shell-model configuration spread over many levels. The sum of the B(GT) values deduced from the present γ-ray data amounts to 0. 34, which provides a lower limit to the total Gamow-Teller strength. The B(GT) distribution for 103In decay is compared to the corresponding experimental results for 105,107,109In and to theoretical predictions for 99,101In. The latter were calculated by using an advanced spherical shell model. The β-branching ratio for the 103m In decay is estimated and compared with the relevant values for the neighbouring indium isotopes including 101In whose half-life was determined to be 14. 9 ± 1.2 s.