Levels and transitions in 140Ba populated following the β decay of 140Cs

Levels in 140Ba were populated following the β decay of 140Cs(Tsub(1/2) = 64 s) which was produced by the on-line fission product mass separator OSTIS at the Institut Laue-Langevin. Gamma data were recorded in an event-by-event mode and the coincidence results enabled a decay scheme with 52 levels up to 5.8 MeV to be established. Directional correlation measurements were made on 14 direct cascades and 11 skip cascades, all in coincidence with the 21+ to 01+ ground-state transition. Definite spin assignments were made for 14 levels and tentative assignments for 5 levels, with multipole mixing ratios being extracted where applicable. In addition, approximate log ft values were calculated for all the β-fed levels and these, together with the relevant modes of decay, were used as a basis for tentative assignments for all but two of the levels not studied using the correlation technique. (author)