Lifetime measurements of the 3D3/2 and 3D5/2 metastable states in CaII

The lifetime of the metastable 3D3/2 and 3D5/2 states of Ca+ ions is determined in a r.f. ion trap by laser excitation of this levels and subsequent time delayed probing of the state population by a second laser. In a buffer gas atmosphere of about 10−5−10−6 mbar of He we observe quenching to the ground state and strong finestructure mixing of the two D-states. This mixing allowes only the determination of the combined lifetime. Our result of τ(3D)=1.24(39) s is in good agreement with theoretical calculations.