Inter- and intrachannel exchange interference in photoinduced Auger decay: The Kr M-4,M-5-N1N23 and Xe N-4,N-5-O1O23 cases g

We study interference effects that appear in the cross section due to detection of two indistinguishable electrons in a photoelectron-Auger-electron pair (intrachannel exchange interference), or due to detection of two indistinguishable photoelectron-Auger electron pairs that share the final state but are emitted via two different intermediate states (interchannel exchange interference). For photoinduced Kr M-4,M-5-N1N23 (Xe N-4,N-5-O1O23) Auger decay, the intrachannel exchange interference is "switched on" at 131.3 eV (87.0 eV) and 133.8 eV (91.0 eV) photon impact energy for the M-5 (N-5) and M-4 (N-4) holes, respectively. The interchannel exchange interference is expected to appear at 132.6 eV (89.0 eV) when the photoelectron ejected from the M-4 (N-4) subshell is emitted with the same energy as the Auger electron emitted in the decay of the M-5 (N-5) hole, and vice versa, the energy of the photoelectron ejected from the M-5 (N-5) subshell equals the energy of the Auger electron emitted in the decay of the M-4 (N-5) hole. We use the approach of Vegh and Macek [Phys. Rev. A 50, 4031 (1994)], and Vegh [Phys. Rev. A 50, 4036 (1994)] to model these phenomena in a unified manner and examine their effects in an angle-resolved and angle-integrated coincidence spectra considering also the postcollision interaction (PCI). The previous and the present angle-resolved experimental results, together with the data obtained by a magnetic bottle time-of-flight spectrometer, indicate that in this particular case the exchange interference effects in the angle-integrated cross sections are considerably weaker than in the angle-resolved (gamma,2e) cross sections.