Autoionization and interchannel mixing in atomic fluorine: The 2p(4)(S-1)ns,md Rydberg series

Experimental data on the spectroscopic and dynamic properties of the 2p(4)(S-1)ns,md series between the D-1 and S-1 thresholds of atomic fluorine are presented. These series are observed through their decay into the allowed 2p(4)(P-3)epsilon l and 2p(4)(D-1) epsilon l ionization channels. The (S-1)ns S-2 resonances are broad windows, and the (S-1)md(2)D resonances are narrow peaks in the principal 2p(4)(D-1)epsilon l channel. The 2s2p(6) S-2 resonance is located at 20.99(1) eV and is seen to interact strongly with the nearby 2p(4)(S-1)4s S-2 resonance. The resulting structure can serve as a sensitive marker for this interchannel mixing. Except for the interacting resonances, the data are found to be in satisfactory accord with eigenchannel R-matrix results for the total cross section.