Chunfang Wang

Newβ-delayed proton precursor135Gd

Unknownβ-delayed proton precursor135Gd has been synthesized by the reaction106Cd (32S, 3n) and identified using a helium-jet recoil fast tape-transport system with aγ(X)-p coincidence measurements. Itsβ-delayed proton spectrum has been observed. The half-life of135Gd decay has been determined to be 1.1±0.2 s.

Neaw β-delayed proton precursor121Ce near the proton drip-line

Unknown β-delayed proton precursor121Ce was produced via the reaction of92Mo(32S, 3n), and identified by an He-jet fast tape transport system with “P-γ” coincidence measurements. The half-life of121Ce decay was determined to be (1.1 ± 0. l)s. Its energy spectrum of β-delayed protons was measured and the β-delayed proton branching ratio for121decay was roughly estimated to be ∼ 1 %. After β-delayed proton decay of the precursors119Ba,121Ba and122La, some of γ-transitions from low-lying states to the ground states in their “daughters” were observed for the first time.