Deformation of the proton emitterCs113from electromagnetic transition and proton-emission rates

Abstract

The lifetime of the (11/2 +) state in the band above the proton-emitting (3/2 +) state in 113 Cs has been measured to be τ = 24(6) ps from a recoil-decay-tagged differential-plunger experiment. The measured lifetime was used to deduce the deformation of the states using wave functions from a nonadiabatic quasiparticle model to independently calculate both proton-emission and electromagnetic γ-ray transition rates as a function of deformation. The only quadrupole deformation, which was able to reproduce the experimental excitation energies of the states, the electromagnetic decay rate of the (11/2 +) state and the proton-emission rate of the (3/2 +) state, was found to be β 2 = 0.22(6). This deformation is in agreement with the earlier proton emission studies which concluded that 113 Cs was best described as a deformed proton emitter, however, it is now more firmly supported by the present measurement of the electromagnetic transition rate.

TPEN: A Triple-foil differential Plunger for lifetime measurements of excited states in Exotic Nuclei

“…Therefore, if recoil tagging techniques were employed for the reaction described in this work, then the overall beam-time improvement using TPEN would be a factor of ∼ 3.5 × 0.66 = 2.3 relative to using a two-foil conventional plunger. As two-foil plungers have performed tagged lifetime measurements in nuclei with production cross-sections of 10 − 20µb [7,22], TPEN would therefore be capable of performing tagged lifetime measurements in nuclei with production cross-sections down to ∼ 4 − 8µb.…”