Transition probability measurements in 52132Te 80: The systematics of E2 transition rates in neutron-rich even Te nuclei

Abstract

Levels in 132Te were populated in the 2.8 and 4.2 min β-decays of 132Sb produced using the OSIRIS on-line isotope separator. The half-lives of the 1774 keV 6 + and 1925 keV 7 − states in 132e were studied using the delayed coincidence method. Conversion coefficients were measured for the 151 keV 7 − → 6 + E1 and the 103 keV 6 + → 4 + E2 transitions. The T 1 2 for the 6 + state was deduced to be 145 ± 8 ns, which implies that B(E2; 6 + → 4 +) = 132 ± 8 e 2 · fm 4. The T 1 2 for the 7 −3 state was determined to be 9 ± 2 μs , giving a hindrance factor of 1.2 × 10 8 compared to the Weisskopf estimate. The result is interpreted in terms of two-particle configurations: v( h 11 2 −1 , d 3 2 −1) 7− and π( g 7 2 2 6 + . The systematics of E even tellurium isotopes are discussed and comparison is made with available microscopic and macroscopic theories.