THE HALF-LIVES OF THE 243-keV AND 188-keV LEVELS IN 125I

Abstract

The half-lives of the 243-keV and 188-keV levels in ¹²⁵I were measured, yielding T_1/2 = 2.1 ± 0.2 × 10⁻¹⁰ seconds for the 243-key level and T_1/2 = 3.4 ± 0.2 × 10⁻¹⁰ seconds for the 188-keV level. Partial half-lives were calculated, indicating that the E2 transition rates are enhanced over single-particle estimates by a factor of 30 and hence are collective in nature.