Remeasurement of the half-life of the 615 keV level in 181Ta

C. C. Dey

doi:10.1140/epja/i2003-10229-5

EPJ

Remeasurement of the half-life of the 615 keV level in ¹⁸¹Ta

C. C. Dey^*

Saha Institute of Nuclear Physics 1/AF, 700 064, Bidhannagar, Kolkata, India

Abstract

The lifetimes of the 615 and 619 keV levels in ¹⁸¹Ta have been remeasured by using a

delayed coincidence set up with fast plastic (Pilot U) and BaF₂ detectors. The presently measured values for both levels have been found to be in strong disagreement with results reported earlier. For the 615 keV level, the half-life has been found to be

ns in striking contrast to the earlier reported value of 17.6

s. The half-life of the 619 keV level has been found to be

ps, whereas values of 0.87 ns and 2.4 ns were reported previously. The nanosecond half-life of the 615 keV level has been confirmed from a separate measurement by employing a NaI(Tl)-Pilot U detector combination. The importance of lifetime measurements for the 615 keV level in perturbed angular correlation studies is discussed.