Experimental study of LS coupling along isoelectronic sequences

In order to test the prediction of the LS coupling approximation for severa l light elements (B, C, N, O, F and Ne), the line intensity ratios of the 3 s-3p multiplets along the isoelectronic sequences of lithium and beryllium and line intensity ratios of 3s-3p and 3p-3d multiplets along isoelectronic sequences of boron, carbon, nitrogen, oxygen and fluorine have been invest igated experimentally. The light sources were two low-pressure pulsed arcs. The plasma electron densities were determined from the width of the He II Px line.