Die Hyperfeinstruktur der Ba II-Resonanzlinien und die Quadrupolmomente der ungeraden Bariumisotope

Abstract

By means of a photoelectric registrating Fabry-Pérot-interferometer and using enriched Ba-isotopes the hyperfine structure of the barium II-resonance lines 6p ² P _3/2,1/2-6s ² P _1/2,λ λ4554; 4934 å has been investigated. The following results were obtained by digital data processing of the registrated interference curves:A(¹³⁵Ba, 6s ² S _1/2)=119.78(10) mK,A(¹³⁷Ba, 6s ² S _1/2)=133.94(11) mK,A(¹³⁵Ba, 6p ² P _1/2)=22.14 (8) mK,A(¹³⁵Ba, 6p ² P _3/2)=3.77(7) mK, andB(¹³⁵Ba, 6p ² P _3/2)=2.1 (3) mK. For the quadrupole moment of¹³⁵Ba we calculated the valueQ(¹³⁵Ba)=0.17(2) · 10⁻²⁴ cm² (without Sternheimer correction). This result should not be strongly affected by perturbations in thep-terms of alcalilike spectra of heavy elements and by the uncertainty of the relativistic corrections. The isotope shift of the odd Ba-isotopes with respect to¹³⁸Ba has been remeasured.