Eur. Phys. J. A (2005) 23: 481-490
https://doi.org/10.1140/epja/i2004-10112-y

The βdecay of ¹⁴⁷Cs to ¹⁴⁷Ba

¹ Department of Detectors and Nuclear Electronics, Sołtan Institute for Nuclear Studies, 05-400, Świerk, Poland
² Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681, Warsaw, Poland
³ Department of Radiation Sciences, Uppsala University, 611 82, Nyköping, Sweden
⁴ Oliver Lodge Laboratory, University of Liverpool, L69 3BX, Liverpool, UK
⁵ Department of Nuclear Spectroscopy, Sołtan Institute for Nuclear Studies, 05-400, Świerk, Poland

^* e-mail: syntfeld@ipj.gov.pl

Received: 23 August 2004
Accepted: 30 November 2004
Published online: 18 January 2005

Abstract

The β^--decay of ¹⁴⁷Cs to ¹⁴⁷Ba has been studied by means of γ- and X-ray spectroscopy. A new level scheme of ¹⁴⁷Ba is significantly modified and extended in comparison to the one previously reported. The Advanced Time-Delayed βγγ(t) method has been applied to measure half-lives of the 46.2 and 85.4 keV levels in ¹⁴⁷Ba yielding T _1/2 of 510(80) ps and 370(100) ps, respectively. The lifetime results combined with the deduced internal conversion coefficients allowed to assign M1 multipolarity to three γ transitions. The B(M1) values obtained for the 39.2, 46.2 and 85.4 keV transitions range from 0.017 to 0.043 W.u. and represent typical B(M1) strength in the Ba-Er region. Model calculations using a shell correction approach with the axially deformed Woods-Saxon potential predict for ¹⁴⁷Ba an octupole deformed ground state with β₃ = 0.11.