Nuclear Structure Models And Bohr-Mottelson Rotational Spectral Theory

This thesis firstly introduced some nuclear structure models and their application. Then, Three methods of diagonalization in quantum mechanics and calculation of shell model were discussed. Lastly, we researched the relation of the parameters of Bohr-Mottelson rotational spectra formula, and a new ralation was got.Firstly, we introduce shell model, collective movement model, particle-rotor model and project shell model. As special topic, we discussed cranking shell model, BCS method of pairing force,spin assignment of rotational spectra and inertia analysis and new development of identical bands.In quantum mechanics, diagonalization is the process of extracting eigenvalue and eigenstate of mechanical quantity. We classified the diagonalization as three sorts, namely diagonalization in own representation, diagonalization in other representation and computational method. The level scheme of spin-orbit coupling shell model was calculated. Using computational method, wo calculate Nilsson diagram which is very important in researching nuclear structure, and wave function of some levels was also given.Lastly, using four-parameter Bohr-Mottelson formula, we analyzed some ground rotational bands of even-even nuclei. The nuclei included superdeformed(SD) nuclei in A-150 , 190 regions and normal deformed(ND) nuclei in actinide and rare-earth. The parameters obtained by the least-square fitting deviate from the relations derived from ab formula , abc formula and Harris formula, but are closer to relations deduced from ab formula and abc formula. Additionally, the relations to parameters of SD bands are similar to those of ND bands. Based on researching the relation of the parameters of Bohr-Mottelson rotational spectra formula from two-parameter Harris Formula, in this thesis three-parameter Harrisformula was used and a new ralation of the parameters of Bohr-Mottelson rotational spectra formula was brought forward. Four-parameter I(I+1) expansion was used to calculate superdeformed(SD) bands of even-even nuclei in A~60, 80,130,140,150,190 regions and normal deformed (ND) bands of nuclei in actinide and rare-earth, the relation of the parameters was discussed. Comparatively, The new relation is consistent with experiment.