Determination of the isotope shift of115m Cd by a Zeeman scanning method

We have used an optical pumping-Zeeman scanning technique in order to determine the isotope shift in the 3,261 Å resonance line of 43-day, spin-11/2^115m Cd. A sample of ≈5×10¹² atoms was aligned in the¹ S ₀ diamagnetic ground state by optically pumping the sample with one selected Zeeman-scanned component of the³ P ₁?3,261 Å resonance line from a¹¹⁴Cd lamp. The alignment was detected through the modulation of the pumping beam at the nuclear resonance frequency. Thus by Zeeman scanning theF = 9/2 component of the³ P ₁ level and using previously determinedA- andB-values, we findδ5v(114–115m (9/2))= ?4,234(48) MHz and¹¹⁴Cd-^115mCd isotope shift = 87(48) MHz. We calculate a staggering parameterγ(^115mCd)=0.73(26), and a change in mean-square nuclear charge radiusδ〈r ²〉^114,115m =0.035(18)fm².