Spectator-electron behavior during cascade decay in krypton

We report new measurements of Kr^q+ photo-ions, coincident with Kα or Kβ fluorescence as incident-photon energy is swept through the Kr K-shell threshold. From the branching ratios just above threshold, we obtain measurements of the ion charge-state probabilities for decay from the Kr [2p] and Kr [3p] states. In the threshold region, we observe both resonant enhancement and depletion of the branching ratios. By analyzing this behavior in light of theory, we extract sticking probabilities, which we feel are a useful set of parameters for investigating the general relationship between cascade decay from resonant and nonresonant hole states. A simplified theoretical model is employed to calculate these probabilities for the Kr²⁺ and Kr³⁺ cases.