Collinear two-step laser excitation: determination of the oscillator strength for the 17 434–34 634-cm^−1 transition in ^238U ii

Abstract

The feasibility of direct determination of optical oscillator strengths in free atoms and ions has been investigated using two-step laser excitation in a collinear fast-beam geometry. Experimental results obtained in the uranium ion are analyzed within the density-matrix formalism. A Rabi frequency Omega = 5.8 +/- 0.8 MHz is found for the 17 434(j=1(1/2))-34 634(J=1(1/2)) transition in (238)U II, corresponding to an oscillator strength f 8.6 x 10(-4) +/- 3.3 x 10(-4) for this transition.