Inner-shell photoexcitation in an open-shell atom: The Cl 2p -> ns,md spectrum as a case study

The 2p-->ns,md excitation spectrum has been measured and calculated for the open-shell C1 atom. A satisfactory accord between experiment and theory wa s found. Rydberg series cannot be discerned for transitions leading to a 2p , 3p, n iota open-shell configuration. The 4s,3d manifolds are dominant, an d the 2p-3p coupling is seen to be much stronger than the 3p-n iota couplin g. Very narrow widths, 16 to 22 meV, for the 4s and 3d lines an observed. B y contrast, only broad structures appear in the region of the highest excit ations. [S1050-2947(99)50302-8].