The and delayed proton decays of mass separated A=141 isotopes with Z=6366 were investigated with an on-line mass separator. Branching ratios have been redetermined for the total decay of the 2.7(3) s, (11/2- isomer Eum141 at 96.5 keV (13-2+4%), and for the direct feeding of the 1.58 keV (3/2+ level of Sm141 in the decay of 40-s Eug141 [73(5)%]. Detailed decay schemes have been constructed for the decays of the (11/2- isomer Gdm141 [11(2) isomeric transition] and the (1/2+ ground state, Gdg141. Half-lives of 24.5(5) s and 14(4) s, respectively, have been determined for these isomers. A delayed proton branch of 0.03(1)% was identified in the decay of Gdg141. A detailed decay scheme was also constructed for 3.5(2)-s Tb141 and a J=(5/2- was assigned to its ground state, at variance with the systematics of heavier, odd-mass Tb isotopes. All -ray assignments to the various isotopes are based on x and coincidences and on half-life measurements. A 0.9(2)-s half-life for Dy141 was determined from its delayed proton decay. All spin assignments proposed in this paper are discussed in terms of Nilsson level diagrams and nuclear shapes.
ASJC Scopus subject areas
- Nuclear and High Energy Physics