Observation of an intensity anomaly in the 3s23p 2P1/2, 3/2-3s3p22S1/2 and 2P1/2 resonance transitions in the Al I isoelectronic sequence
The intensity ratio of the two fine structure components in the 3s23p 2PJ–3s3p 2S1/2 and 2P1/2 resonance transitions has been measured in Al-like S IV, Cl V, Ar VI and Ti X, using the beam-foil technique. Unexpectedly large deviations from the LS ratios are found, particularly in the 2P–2S case. Although these deviations can be understood qualitatively from theoretical calculations (also reported)