DECAY PROPERTIES OF GROUND-STATE AND ISOMER OF IN-103

The beta-decay properties of ground-state and isomer of In-103 were in vestigated by means of gamma-ray spectroscopy. The half-lives of In-10 3g and In-103m were determined to be 60 +/- 1 s and 34 +/- 2 s, respec tively. Out of 149 gamma transitions ascribed to the decay of In-103g, 104 have been placed in a decay scheme including 55 excited states nf Cd-103g. The man part of the resulting distribution of the Gamow-Tell er strength B(GT) is associated with the feeding of Cd-103 levels at e xcitation energies around 3 MeV. This observation can be interpreted a s a sign of dominant feeding of three-quasiparticle states in Cd-103, which correspond to the 1(+)(pi g(9/2)(-1),nu g(7/2))x pi g(9/2) shell -model configuration spread over many levels. The sum of the B(GT) val ues deduced from the present gamma-ray data amounts to 0.34, which pro vides a lower limit to the total Gamow-Teller strength. The B(GT) dist ribution for In-103 decay is compared to the corresponding experimenta l results for In-105,In-107,In-109 and to theoretical predictions for In-99,In-101. The latter were calculated by using an advanced spherica l shell model. The P-branching ratio for the In-103m decay is estimate d and compared with the relevant values for the neighbouring indium is otopes including In-101 whose half-life was determined to be 14.9 +/- 1.2 s.