The half-life of the 453.08 keV level in 183W

Abstract

The half-life of the 7 2 7 2 −[503] level at 453.08 keV in 183W was measured from the decay of 183Re to be T 1 2 = 19.0±0.6 ns , yielding the absolute gamma-ray transition probabilities of transitions to seven different levels. The following hindrance factors relative to the single-particle Weisskopf estimate F W and the Nilsson estimate ( F N for K-allowed transitions) were obtained: E2, ΔK = 2 transitions to the 7 2 , 5 2 and 3 2 rotational members of the 3 2 −[512] intrinsic state F W = 29±10, 79±56, 20±2, F N = (2.6±0.9)×10 −2, (6.8±5.0)×10 −1, (6.8±0.7)×10 −2, respectively; once K-forbidden M1 transitions to the 7 2 and 5 2 rotational members of the 3 2 −[512] level F W = (1.2±0.2)×10 4 and (3.8±0.4)×10 4; twice K-forbidden M1 transitions to the 9 2 , 7 /2 and 5 2 rotational states of the 1 2 − [510] Nilsson level F W = (9.6±1.0)×10 4, (4.5±0.4)×10 4 and (3.3±0.5)×10 5, respectively, and once K-forbidden E2 transitions to the 9 2 , 7 2 , 5 2 and 3 2 rotational members of the 1 2 −[510] intrinsic state: F W ≧2.5×10 2, ≧1.1×10 3, ≧6.9×10 2 and ((4.4±0.5)×10 3 . The hindrance factors F N of the E2, ΔK = 2 transitions are compared with other known E2, ΔK = 2 gamma-ray transition probabilities in deformed odd-mass nuclei. The half-life of the 453.08 keV level in connection with the upper limit given for the gamma-ray transition to the 309.49 keV state suggests the interpretation of the 309.49 keV level as the 11 2 11 2 +[615] Nilsson level instead of 9 2 9 2 +[624] .