Hyperfeinstrukturaufspaltung und Lebensdauer des 7² P _3/2-Terms von Rb⁸⁵ und Rb⁸⁷

Abstract

The hyperfine structure splitting of the 7² P _3/2 state of Rb⁸⁵ and Rb⁸⁷ has been measured with optical double resonance. The following hfs interaction constants have been obtained: Rb⁸⁵:A ⁸⁵_7p =3.71(1) MHz;B ⁸⁵_7p =3.68 (8)MHz. Rb⁸⁷:A ⁸⁷_7p =12.57(1) MHz;B ⁸⁷_7p =1.71 (3)MHz. These values yield quadrupole moments ofQ ⁸⁵_7p,hfs =+0.316(7) barn andQ ⁸⁷_7p,hfs =+0.147(2)barn which are reduced by application of the Sternheimer correction toQ ⁸⁵_7p =+0.267(6) barn andQ ⁸⁷_7p =+0.124(2) barn. The averaged ratio of the uncorrected values of Q_hfs in the 5p and 7p ² P _3/2 stake isQ _5p,hfs/Q _7p,hfs=1.07(3). This has to be compared with the correction factors for polarization of the core of electrons by the nuclear quadrupole moment (1−R)_5p/(1−R)_7p=1.07. The agreement between the measured and calculated ratio indicates a net antishielding of the nuclear quadrupole moments of rubidium by the core of electrons as has been predicted bySternheimer. The lifetime of the 7² P _3/2 state of the RbI-spectrum is:τ(7² P _3/2, Rb)=2.4(2)·10⁻⁷ sec.