A high-resolution angle-resolved electron spectroscopy study of the 5dnp Rydberg series in Ba

Angle-resolved measurements of the autoionization electrons from the decay of the 5dnp resonances in the wavelength region just above the first ionization limit of barium are presented. We have used a UV laser to provide high resolution and almost 100% plane-polarized light. Angular distribution parameters measured at the peak positions for some of the resonances are compared with the values expected for pure jK and jj couplings and with theoretical values obtained by R-matrix calculations. Experimental angle-resolved autoionization profiles are also compared with theoretical calculations.