Oscillator Strength Measurements of Even-Parity Autoionizing Resonances by Combined Synchrotron-Radiation-Laser Excitation

Abstract

We have obtained oscillator strengths for transitions between a laser-excited initial state and autoionizing final states. In the case of sodium, a laser was used to populate the $3p$ initial state, and synchrotron radiation was used to excite the autoionizing resonances. These transitions are of the type $2{p}^{6}3p^{2}P\ensuremath{\rightarrow}2{p}^{5}(^{2}P)3s3p(^{1,3}P)^{2,4}S,^{2,4}P,^{2,4}D$; they decay to $2{p}^{6}^{1}S+e$. The sum of the oscillator strengths for all the observed transitions between the $2{p}^{6}3p$ initial-state and the $2{p}^{5}3s3p$ final-state configurations was found to be equal to 0.22(4).