High-spin states in 161Er have been studied experimentally via the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. Three rotational bands built on the 5/2+[642], 3/2-[521], and 11/2-[505] configurations have been extended up to high-spin states, and particularly, the α = -1/2 branch of the ground state 3/2-[521] band has been revised significantly. It is found that signature inversion occurs in the 3/2-[521] band after the band crossing in 161Er. The systematics of the signature inversion associated with the 3/2-[521] configuration in the rare-earth region is discussed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and a triaxial deformation is proposed to the 3/2-[521] band.
CHEN Liang1,2, ZHOU XiaoHong1,2, ZHANG YuHu1, ZHANG ShuangQuan3 & ZHU LiHua4 1Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
Theoretical calculations have been performed for the ν9/2+[624](i13/2) and ν7/2-[503](f7/2) bands of 185Pt in the framework of particle-rotor model. The band properties of signature splitting and configuration mixing have been analyzed. The level energy and signature splitting before the band crossing can be well interpreted by introducing triaxiality. The positive-parity yrast band is pro posed to be dominated by the ν9/2+[624](i13/2) component, while the negative-parity band shows strong mixing of ν7/2-[503](f7/2) and ν9/2-[505](h9/2) configurations.
LI GuangShun1,2, ZHOU XiaoHong1,2, ZHANG ShuangQuan3, ZHANG YuHu1 & MENG Jie3 1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
Charge stripping is employed to produce multi-charged ions for injecting the cooling storage ring.After penetrating through the carbon foil,the widened distribution of ion charge states poses a limit to the ion injection.Therefore,the carbon foil plays a key role in the charge stripping injection.In this paper,four strippers for Heavy Ion Research Facility at Lanzhou(HIRFL) and Cooling Storage Ring(CSR) are introduced.The charge state distribution of the stripped ions is measured and the stripping efficiency of the foils is investigated.The experimental results are consistent with the theoretical values.
ZHANG Hongbin XIAO Guoqing YUAN Youjin XU Hushan LI Zhankui LU Ziwei MAO Ruishi ZHAO Tiecheng
Pellet target is one of the main candidate targets in CSRm (cooler storage ring’s main ring) for hadron physics studies. Pellet speed is an important physical parameter for the target. Larger pellet speed could shorten the interacting time interval between the pellet and the cyclotron beam, and thus results in a small temperature variation for the pellet. This could make the pellet facility work in a stable condition. A fluid dynamic simulation was carried out for the pellet speed, and it was found that the maximum speed for the target pellet may be restricted to about 100 m/s even if all working parameters were set to their optimal values.
High-spin states in 161Er have been studied experimentally using the 150Nd（16O, 5n） reaction at a beam energy of 86 MeV. The relatively enhanced E1 transitions between the 5/2＋[642] and 3/2-[521] bands are observed in 161Er, and the B（E1） values are extracted experimentally. The systematics of the R（E1） values in the N = 93 isotones are presented. It is found that the strength of the E1 transitions obviously exhibits angular momentum dependence, and the occurrence of the relatively enhanced E1 transitions could be attributed to octupole softness.
