Experimental Determination of Auger-Decay Amplitudes from the Angular Correlations in Auger Cascade Following the 2p-->4s Photoexcitation in Ar

We have determined the ratio of the s and d Auger-decay amplitudes and their phase difference for the resonant Auger transition 2p 3 24s ! 3s213p214s 2P from the measurement of the angular correlation between the resonant Auger emission and the subsequent second-step Auger emission, as well as the angular distribution measurements for these two electron emissions. The analysis of the experimental data is based on the nonrelativistic LSJ coupling approximation.