We report a new high-precision lifetime measurement of the first excited 5/2+ state of 133Cs using NaI(Tl) and LaBr3(Ce) detectors. The time difference between the coincident decays of two successive states was measured using fast-timing electronics. The 356-keV (1/2+→5/2+) gamma transition was tagged by the successive 81-keV (5/2+→7/2+) transition of 133Cs. The half-life of the first excited 5/2+ 133Cs state was measured as T1/2=6.283±0.004 (stat.) ±0.011(syst.) ns.
Bibliographical noteFunding Information:
We are greatly indebted to J.M. Lee at KRISS for providing a 133 Ba radioactive source encapsulated in a thin film. This work was supported in part by the National Research Foundation of Korea and Korea University .
- LaBr(Ce) scintillator
- NaI(Tl) scintillator
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