Zero-field hyperfine structure measurements of the metastable states 3d ² 4s ⁴ F _{3/2, 9/2} of⁴⁵Sc using laser-fluorescence atomic-beam-magnetic-resonance technique

Abstract

In an atomic beam experiment we measured the hyperfine structure (hfs) of the metastable states 3d ² 4s ⁴ F _3/2,9/2 of Scandium, which were populated by electron impact. A single mode cw dye laser was used to create a population difference between neighbouring hfs states by optical pumping. Rf transitions between these states, equalizing the population numbers, could then be detected by repeating the optical pumping experiment and looking for the laser induced fluorescent light. The following constants of the magnetic dipole and electric quadrupole interactions have been obtained by this method:A _3/2=−158.513(3)MHzB _3/2=−5.19(2)MHzA _9/2=285.967(9)MHzB _9/2=−15.46(70)MHz

From these constants and the corresponding values forJ=5/2, 7/2, as measured by [1], the following parameters can be calculated: 〈r ⁻³〉 ⁰¹ _d =0.911(4)a ⁻³₀ 〈r ⁻³〉 ¹² _d =2.395 (62)a ⁻³₀ and:α=〈r ⁻³〉 ⁰¹ _d /〈r ⁻³〉 ¹² _d =0.38(1).