Electric quadrupole transition strengths of the type 6 +1 → 4 +1 in 106–112Sn

Abstract

Nanosecond isomers in 106,110,112Sn and 107Cd are investigated by the bombardment of 106,110,112Cd with 29MeV 3He ions. Thereby, the following half-lives of states with J π = 6 + 1 are determined: T 1 2 (2323.6 keV in 106 Sn) = 2.8 ±0.5 ns , T 1 2 (2477.0 keV in 110 Sn) = 5.6 ± 0.4 ns and T 1 2 (2548.9 keV in 112 Sn) = 13.8 ±0.4 ns . Further, T 1 2 (205.0 keV in 107 Cd) = 0.7 ±0.1 ns was derived. Calculations of level energies and transition rates are performed within the quasiparticle-phonon model. The experimental B(E2, 6 + 1 → 4 + 1) values in 106–112Sn are reasonably reproduced within this model revealing thereby the importance of weak two-phonon components. Some level energies and transition rates in 106–112Sn ( Z = 50) and their corresponding valence mirror partners with N = 82 are compared and discussed.