The Relativistic Study of Hyperfine Interactions in Ionic Systems.
Abstract
The BruecknerGoldstone perturbation theory as formulated relativistically has been applied to the study of hyperfine interactions in the lithiumlike ions Li ^0, Be^{+1}, B^{+2}, C^ {+3}, N^{+4} , O^{+5}, F ^{+6}, Ne^{+7 } and Bi^{+80}; in the alkaline earth ions Ra^+ and Sr^+; and in the Group 12 ions Zn^+, Cd^+, and Hg^+, isoelectronic with the Group II atoms Cu, Ag, and Au. We have employed the graphical representation of the theory, where Feynman diagrams are associated with physical effects such as the valence, exchange core polarization, the consistency, and correlation. Contributions from radiative effects are estimated for these systems using a hydrogenic model. The contributions of both exchange core polarization and correlation as ratios of the valence contribution decrease as the degree of ionization and nuclear charge increase; the decrease in much more rapid for the correlation effect. Radiative effects, on the other hand, increase very rapidly with increasing charge, becoming of the same order of magnitude as correlation effects in O^{+5}. For Bi ^{+80} the radiative effect is 0.3% of the valence electron's contribution to the hyperfine field and is larger than the correlation. Our purpose in calculating the hyperfine field for the ^ {213}Ra^+ ion is to evaluate magnetic moments of other Ra isotopes from experimentally determined ratios of magnetic moments. The total hyperfine field obtained for ^{213 }Ra^+ is 1232 tesla (T); when combined with the experimental hyperfine constant from Zeeman measurements, this yields a nuclear magnetic moment of 0.610 +/ 0.006 mu_{rm N}, where mu_{rm N} is the nuclear magneton. Calculations for Zn^+, Cd^+, and Hg^+ have been performed in order to compare the trends of various contributions to the hyperfine fields for these systems from different mechanisms with those of alkali atoms and alkalineearth ions. Our calculated hyperfine fields of Zn^+, Cd^+, and Hg^+ are 451 +/ 9 T, 795 +/ 15 T, and 2642 +/ 63 T, respectively. For these systems, the contributions to the total hyperfine field from different mechanisms are compared with those calculated for alkaline earth ions and alkali atoms which have a single electron outside the closed shell. The importance of diagrams of the third and fourth orders are discussed in this context. (Abstract shortened with permission of author.).
 Publication:

Ph.D. Thesis
 Pub Date:
 February 1991
 Bibcode:
 1991PhDT........80P
 Keywords:

 Physics: Atomic