Measurement of the half-life of excited nuclear states using liquid scintillation counting

Chavdar Dutsov; Benoît Sabot; Philippe Cassette; Krasimir Mitev

doi:10.1016/j.apradiso.2021.109845

Measurement of the half-life of excited nuclear states using liquid scintillation counting

Appl Radiat Isot. 2021 Oct:176:109845. doi: 10.1016/j.apradiso.2021.109845. Epub 2021 Jul 1.

Authors

Chavdar Dutsov¹, Benoît Sabot², Philippe Cassette³, Krasimir Mitev³

Affiliations

¹ Sofia University "St. Kliment Ohridski", Faculty of Physics, 5 James Bourchier Blvd, 1164, Bulgaria. Electronic address: ch.dutsov@phys.uni-sofia.bg.
² Université Paris-Saclay, CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91120 Palaiseau, France.
³ Sofia University "St. Kliment Ohridski", Faculty of Physics, 5 James Bourchier Blvd, 1164, Bulgaria.

PMID: 34229146
DOI: 10.1016/j.apradiso.2021.109845

Abstract

This work presents measurements of the half-lives of excited nuclear states of ²³⁷Np and ⁵⁷Fe using a liquid scintillation (LS) spectrometer and a gamma detector. A novel approach for the determination of the half-lives of some excited states is presented which uses only LS counting data from a detector with two PMTs. The lifetime of the 1st and 2nd excited states of ⁵⁷Fe were obtained without the use of a gamma detector. The obtained value for the 59.54 keV level of ²³⁷Np is 67.60(25) ns. The obtained values for the 14.4 keV and 136.5 keV levels of ⁵⁷Fe are 97.90(40) ns and 8.780(36) ns, respectively. The half-life results from this study are consistent with the average value found in the reference decay data tables and have a lower uncertainty.

Keywords: Fe-57; Half-life measurements; LSC; Liquid scintillation; Np-237.