Theoretical Study On Odd A Isotopes Energy Level With Particle-Triaxial-Rotor Model

The particle-triaxial-rotor model has a very important position in many theoretical models which are used in the nuclear structure research. It was presented by Aage Bohr. Then Davydov and many other people made important contributions for the model's development. At early time, the model was mainly used in the research of nuclear energy level. Now some researchers studied the signature inversion phenomenon of odd-odd nuclei, multiple chiral doublets theory and isomers with particle-triaxial-rotor model. This paper made theoretical study on the theory of particle-triaxial-rotor model. The Hamiltonian of Odd-A nuclei was written as H = H_core+H_spwhere is the Hamiltonian of even-even core, is the single-particle Hamiltonian under the intrinsic frame(it include the interaction component between the even-even core and the single-particle). We diagonalize the under the strong coupling basis and the single particle basis respectively, and add the corresponding eigenvalue of energy, then we get the nuclear energy structures.This paper derived the theoretical formula carefully, then compiled the calculation codes with FORTRAN computer language, fitted the A¹60 odd A isotopes Ho rotating bands and 229Th energy levels.The results of the calculations showed that there are some good results for partial energy level by fitting the 161, 163, 165Ho and 229Th energy level structure with particle-triaxial-rotor model. This illustrated that the studying on 161, 163, 165Ho and 229Th with particle-triaxial-rotor model is appropriate. There is potential for better result by going on amend it.The structure of this paper as follows:The background of this research direction and the situation now are briefly described in Chapter One. In Chapter Two the theoretical model is discussed. In Chapter Three the theoretical results are compared with the experimental data. At the end, a brief summary is given. A very detailed derivation of the theoretical model is given in Appendix.