Stark Beats in Lyman-Series Emission

Observed intensity fluctuations in the emission of Stark-perturbed $\mathrm{L}\mathrm{y}-\beta$ radiation, from hydrogen atoms formed by passage of hydrogen ions through carbon foils, are compared with theoretical calculations using a density-matrix formalism to yield information on the cross sections for creation into the various $l$ states. It is found, for beam energies between 250 and 500 keV/atom, that the $s$ states are preferentially populated by more than a factor of 4, compared to a statistical distribution. Similar results are also obtained for $\mathrm{L}\mathrm{y}-\alpha$ emission in electric and motional electric fields, in contrast with previous reports at lower energies. The effects of Zeeman splittings, hyperfine interaction, and fringing fields on the signal are investigated.