Study On The Super - Fine Energy Level Of The First Excited State Of Electronic Series Such As Heavy Element Nickel And So On

Hyperfine interaction originates from the interaction between the electromagnetic field of the electrons and the electromagnetic multipole moments of the nucleus. It splits fine structure level into closed-spaced hyperfine levels, according to the new good quantum number F (F=I+J). Hyperfine interaction can change the radiative decay behavior of the hyperfine level. It can mix the hyperfine levels from different fine structure levels, if they are of the same F quantum number. Such off-diagonal mixing effect can open extra decay channel for some hyperfine levels, a phenomenon known as the hyperfine induced transition, and, therefore, shorten the lifetimes of metastable states.In this work, a theoretical investigation is performed to study the lifetimes of different hyperfine levels of the first excited level3d94s3D3in Ni-like isoelectronic sequence (Z=72-79, Hf44+, Ta45+, W46+, Re47+, Os48+, Ir49+, Pt50+,Au51+) for all stable isotopes with nuclear spin. A fully relativistic multi-configuration Dirac-Hartree-Fock method (MCDHF) was employed to study the atomic structure. Hyperfine interaction was included as a perturbation to calculate the wave function of the hyperfine levels.For each isotope with nuclear spin, we calculate the lifetimes of hyperfine levels, investigate the effect of nuclear magnetic dipole and electric quadruple hyperfine interaction on the total lifetime of individual hyperfine level, and discuss the influence of extra E2decay channel on the total hyperfine lifetime. Our investigations on W46+, Re47+and Os48+are of density diagnostic value to the magnetic confined fusion plasmas.It is found that nuclear electric quadrupole hyperfine interaction is important to some hyperfine levels in our investigation. Also, the extra E2transition channel introduced by nuclear magnetic dipole and electric quadrupole interaction is important to the lifetimes of most hyperfine levels in each ion in the isoelectronic sequence. Under the influence of this extra decay channel, lifetimes of most hyperfine levels in Ni-like181Ta,185Re and187Re are drastically shortened by more than an order of magnitude.