Rostock 2019 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 35: Precision Spectroscopy of atoms and ions
A 35.22: Poster
Donnerstag, 14. März 2019, 16:15–18:15, S Fobau Physik
Atomic computations of Isotope Shift Parameters for Heavy Elements — •Randolf Beerwerth1,2 and Stephan Fritzsche1,2 — 1Helmholtz Institut Jena, 07743 Jena — 2Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, 07743 Jena
The isotope shift between two isotopes A and A′ of the same element is parametrized in terms of the mass and field-shift parameters. The former arises due to the nuclear recoil, while the latter is caused by the finite extent of the nuclear charge distribution. Generally, only the lowest order in the expansion of the field shift is considered and this allows to extract differential mean squared charge radii δ <r2 >A, A′ from measured isotope shifts using a known value for the field shift factor F. The field shift factor can be computed to good precision from atomic computations without a detailed knowledge of the nuclear parameters.
We present multiconfiguration Dirac–Hartree–Fock (MCDHF) computations of isotope shift parameters for several heavy elements such as bismuth and gold that are provided to support experimental work. In addition, different strategies for evaluating the accuracy of the computed results are discussed.
Instead of describing the field shift by a single parameter F an expansion into higher-order moments can be utilized. Methods for the computation of the corresponding field shift factors are discussed and possibilities for extracting higher order nuclear moments from experimental data are presented.