Development And Application Of The Extended Projected Shell Model

Recently,with the development of radioactive-beam facilities anddetect-ing devices,it has been a frontier for nuclear astrophysics and nuclear structure to study decays and structures of nuclei at extreme conditions,for instance,extremes of angular momentum etc.The nuclei excitation modes have two kinds:the collec-tive excitation and the single particle excitation.The single particle excitation of deformed nuclei are quasiparticle excitations,and those with high K are called high K isomers due to their long lifetime.High K isomers have possible applica-tions in energy sources and weapons,for which they have developed into one of the popular subject in nuclear physics.The projected shell model?PSM?begin with a deformed Nilsson+BCS quasi-particle states,and then recovers the broken rotation symmetries by angular mo-mentum projection and mixes different quasiparticle configurations by diagonaliz-ing the nuclear system Hamiltonian,wave functions,energy spectra,electro mag-netic transitions probability?etc.?of nuclear system could be obtained.recently,we developed the PSM and applied the developments on nuclear structure.by efficiently calculating the rotated matrix elements by the so called Pfaffian algo-rithm,the configuration of the PSM is expanded to include up to 10 quasiparticle states.This expanded the physics field that the model can study,such as loss of collectivity and the structural changes etc.of nuclei at high spins state.It is shown that the higher order quasiparticle states play very important roles in describing these phenomenons.the structure of neutron-deficient Kr isotopes in=70-80 mass region have been investigated within extended PSM formalism with special interest on high-spin structure of these nuclei.the prolate deformation in the shell-model ba-sis seems to be a well valid approximation for these high-spin regions.This is also supported by some observed cases and our results are consistent with those.The structural evolutions of the yrast and near-yrast side-bands as functions of spin are described by successive band-crossings among 2-qp,4-qp,6-qp and 8-qp states.We have shown that,the inclusion of 6-qp and 8-qp states in the basis are necessary for the detail description of very-high spin states.Moreover,the elec-tric quadrupole transition probabilities have been calculated and compared with available experimental data.The observed variations in?2?are qualitatively described in the calculations.we have systematically analyzed the structure of the high-spin regime as well as multi-qp high-K isomers of even-even^174-186W isotopes.The structure of yrast high-spin levels is analyzed for multi-quasiparticle excitations.Apart from the yrast band,K-isomers and rotational bands based on those are described and their dominant multi-quasiparticle structures are predicted.The electromagnetic properties?e.g.?2?,?1?,g-factor?of the K-isomers are also studied and compared with available experimental data.For most of the K-isomers,the experimental properties are unknown and our results remain as predictions.