Hyperfine structure of23P levels of heliumlike ions

Abstract

A systematic calculation of the hyperfine structure of 2${\mathrm{}}^{3}$P levels of heliumlike ions is presented. Reduced matrix elements of the magnetic-dipole hyperfine operator between substates of the 2${\mathrm{}}^{1,3}$P states are evaluated using relativistic configuration-interaction wave functions that account for both Coulomb and Breit interactions. These matrix elements, together with the energy intervals \ensuremath{\Delta}${\mathrm{E}}_{10}$=E(2${\mathrm{}}^{3}$${\mathrm{P}}_{1}$)-E(2${\mathrm{}}^{3}$${\mathrm{P}}_{0}$), \ensuremath{\Delta}${\mathrm{E}}_{20}$=E(2${\mathrm{}}^{3}$${\mathrm{P}}_{2}$)-E(2${\mathrm{}}^{3}$${\mathrm{P}}_{0}$), and \ensuremath{\Delta}${\mathrm{E}}_{\mathrm{st}}$=E(2${\mathrm{}}^{1}$${\mathrm{P}}_{1}$)-E(2${\mathrm{}}^{3}$${\mathrm{P}}_{0}$), are tabulated for ions with nuclear charges in the range Z=2--100. For Z=2, the matrix elements are in close agreement with precise nonrelativistic variational calculations, but as Z increases from 2 to 10, the present values deviate smoothly from the variational values owing to relativistic corrections. Applications are given to determine the hyperfine structure of $^{3}\mathrm{He}$, $^{6,7}\mathrm{Li}^{+}$, $^{9}\mathrm{Be}^{2+}$, and $^{19}\mathrm{F}^{7+}$. Hyperfine quenching rates of 2${\mathrm{}}^{3}$${\mathrm{P}}_{0}$ states are calculated using a radiation-damping formalism for all stable isotopes in the range Z=6--92. Quenching rates of 2${\mathrm{}}^{3}$${\mathrm{P}}_{2}$ states are also calculated for selected ions. For Z=9--29, the 2${\mathrm{}}^{3}$${\mathrm{P}}_{0}$ quenching rates are in good agreement with relativistic 1/Z calculations. For Z>40, the diagonal hyperfine matrix elements disagree in sign with previously published multiconfiguration Dirac-Fock values. In view of these differences, the present matrix elements are used to reevaluate the fine-structure intervals \ensuremath{\Delta}${\mathrm{E}}_{10}$ inferred from hyperfine quenching experiments for the ions ${\mathrm{Ni}}^{26+}$, ${\mathrm{Ag}}^{45+}$, and ${\mathrm{Gd}}^{62+}$.