Z.G. Gan - Z. Qin - J.S. Guo - L.J. Shi - H.Y. Liu - T.R. Guo - X.G. Lei - R.C. Ma - W.X. Huang - S.G. Yuan - X.Q. Zhang - G.M. Jin
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P.R. China
Received: 11 January 1999 / Revised version: 20 May 1999 Communicated by J. Äystö
The decay of 131Pm has been investigated by means of -ray spectroscopy. The 131Pm nuclei were produced by fusion-evaporation reaction of 106Cd(32S,3p4n) at the beam energy of 170 MeV. A helium-jet technique and a tape transport system were used to collect the activities and transfer them to a detecting position for X and rays measurement. Two rays of 185.0 and 220.0 keV were unambiguously identified to follow the decay of 131Pm by results of X- and - coincidence. A growth-decay feature of the decay curve for 87.8 keV -ray of 131Nd confirmed the production of 131Pm nuclei. The half-life of 131Pm was measured to be 6.30.8 s. A partial decay scheme of 131Pm is proposed on the basis of X- and - coincidence data in this experiment and the known structure information deduced from in-beam experiments of the daughter nucleus 131Nd.
27.60.+j - 21.10.Tg Lifetimes - 29.30.Kv X- and -ray spectroscopy