Investigation Of The Collective Properties For Osmium Isotopes And Motion Mode Along The Yrast Line For Nuclei In Medium And Heavy Mass Region

The main work of this paper is based on the Total-Routhian-Surface cranked shell model.The collective properties in even-even osmium isotopes and the motion mode along the yrast line for nuclei in medium and heavy mass region were systematically investigated using this model.The main content are divided into two parts: Firstly,analysis the deformation and rotational properties for osmium isotopes;studying the rotational properties for 178-188 Os in detail,including the research of deformation,neutron and proton alignment,evolution between vibration and rotation.Secondly,analysis the evolution between vibration and rotation for nuclei in medium and heavy mass region,and reveling the physical mechanism for this evolution.Part one,TRS method was used to calculate the the collective properties for even-even osmium isotopes,including deformation,low-lying level and rotational properties.Through comparing with the experiment data,it is concluded most of these Os isotopes are soft in ? directions and possess prolate deformation.Six nuclei178-188 Os show good rotational properties.Meanwhile,The 186-188 Os exhibit the staggering pattern similar to that of the triaxial ?-rigid model predictions.The calculated quasiproton Routhians and quasineutron Routhians are also made for the186-188 Os,showing that the alignment of the h11/2 proton pair is more favored than that of the i13/2 neutron pair.We have use three simple experimental methods to discuss the collective motions of the nuclei for different spin ranges,showing that the nuclei can evolve from rotation to vibration to rotation again.The discovery of this phenomenon is meaningful for the research on structure evolution.Part two,system research was made on the nuclei evolving from rotation to vibration to rotation,and we use the three simple experiment method to test our research.In addition,in order to get the insight into the rotational-like properties of the nuclei,as an example,shape calculations using the total Routhiansurfaces(TRS)model have been carried out for the nuclei mentioned.Also we have shown that the nuclei becomes soft in ?2 deformations when the vibration motion in dominate.