Identification ofCs147and half-life determinations for Cs and Ba isotopes withA=144

Abstract

Half-life determinations of Rb and Cs fission products available at an on-line mass separator have been made for several neutron-rich Rb, Sr, Cs, and Ba isotopes using both P-multiscale and y-multispectra measurements. The half-lives and rms uncertainties (in sec) are Rb, 0.203+0.

Discovery of the barium isotopes

“…This value is consistent with the presently accepted value of 11.5(2) s. Hahn and Strassmann had speculated about the existence of a short-lived barium isotope (< 0.5 m) [55] which was tentatively assigned to 143 Ba by the Plutonium Project Records [62]. [67]. 147 Ba was produced and identified by neutron induced fission of 235 U at the On-line Separator für Thermisch Ionisierbare Spaltprodukte (OSTIS) facility of the Institut Laue-Langevin in Grenoble, France.…”

Structure in the beta strength function of very neutron-rich Rb-isotopes

“…2). The same effect was observed earlier for core-polarized states in [15,[24][25][26], the dashed lines connect values calculated by the gross theory [8], the full squares correspond to microscopic calculations the y-decay of isobaric analog states in Sc, V, Cu [22,23]. The effect is reproduced by the calculation (Fig.…”

Half-lives, neutron emission probabilities and fission yields of neutron-rich rubidium isotopes in the mass regionA=96 toA=100

“…For 96Rb there is a deviation from earlier values, which exclusively were based on beta or neutron counting. A comparison of the experimental half-lives with predictions fi'om the gross theory of /?-decay [15] shows that the overestimation of the half-lives by this theory, as stated in [7] for rubidium isotopes of mass 95 to 98, continues for 99Rb and l~176 These deviations could be understood by a structure of the beta strength function [17]. Possibly an occurrence of nuclear deformation around A=100 could introduce additional complications.…”