The School of Nuclear Engineering and Technology at the East China Institute of Technology cooperated with the China Institute of Atomic Energy to investigate the high spin states of 84Sr. The study is reported in Volume 53 (October, 2010) of the SCIENCE
We briefly reviewed the experimental study onβ-delayed proton decays near the proton drip line published by our group during the period of 1996-2004, namely the first observation of theβ-delayed proton decays of 9 new nuclides in the rare-earth region (Fig.1)and the new measurements ofβ-delayed proton decays of 5 nuclides in the mass≈90 region near the N = Z line (Fig. 2) with the aid of the 'p-γ'
The experiment was carried out at the Sector-Focusing Cyclotron in IMP. 133Sm was produced via fusion, evaporation in the reaction 40Ca(96Ru,2pn).Itsβ-delayed proton decay was studied by means of 'p-γ' coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra (Fig. 1),γ-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The possible spins and parities of 133Sm were extracted by fitting the experi-
We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2004, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92Rh as well as the predicted “waiting point” nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142Ho and 128Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.
XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2 , CHEN Yongshou 2 , XU Furong 3 , WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
