Post-collision interaction effects of photoelectrons induced by Auger cascades

Abstract

PcL A threshold photoelectron specmm and its component spectra of Auger cascades aRer AI K-shell photoionization have been measxed by wincidenoes between threshold photoelectrons and residual ions of Lhe cascades. These spectra exhibit remarkable profiles of postcollision interaction effects due to the Auger cascades. The peak shift increases gradually according to the tims of interactions. but the peak broadening is almost indepndent of the times of interactions. Tbese p m 6 k a~ analysed in terms of a simple model expressing the pmbability of A u p eleftmu emissions by statistical w e i g hIn near-threshold inner-shell photoionization of atoms, the subsequent Auger decay might be influenced by the presence of a slowly receding photoelectron. This influence is called post-collision interaction ( F a ) .Close to the threshold, the slower photoelectron shields the doubly charged atomic ion so that the faster Auger electron gains energy and, as its counter

Time dependent aspects in the ionizations following atomic photoexcitations

“…We further on compare the present theoretical spectral profiles with experiments by Hayaishi et al [18] in Fig. 4.…”

“…Secondly, we study the multi-electron effects in post-collision interactions after argon K-shell photoionizations, and compare the theoretical result with the experimental result by Hayaishi et al [18]. When we remove Ar 1s electron by photon impact, cascading Auger decay will follow.…”

“…We excluded the comparison of Ar 2+ spectra because the decay process contains a radiative transition, which is outside the scope of the present theory. The results of present theoretical calculations for Ar 3+ to Ar 6+ are represented in solid curves, whereas the TEPICO experimental spectra by Hayaishi et al [18] are given by dotts. The horizontal axis is electron energy deviation in units of electron volt, which is, for the theory, the energy of a photoelectron created by K-shell ionization threshold energy photon impact, and, is, for the experiment, the photon energy measured from K-shell ionization threshold.…”

“…By using the obtained theoretical values, we have calculated the post-collision interaction effects with the help of Eq. (8) for the case of zero excess photon energies, which simulates the threshold photoelectron photoion coincidence (TEPICO) spectroscopy experiment by Hayaishi et al [18]. In Table 1, we illustrate the PCI shifts and broadenings.…”

Influence of double Auger decay on low-energy 3dphotoelectrons of krypton

“…In the case of inner-shell photoionization followed by DA decay, PCI implies the interaction of the emitted photoelectron with the two subsequent Auger electrons and with the field of the ion, which varies during the Auger decay. Previously, PCI effects in DA processes have been investigated experimentally by means of threshold photoelectron yields measured in the vicinity of inner-shell vacancies: Kr 1s −1 , Kr 2p −1 , Kr 3p −1 , Ar 1s −1 , Ar 2p −1 , Xe 4p −1 , and Xe 4d −1 [9][10][11][12][13][14][15][16][17][18]. Also an investigation of PCI-distorted photoelectron lines associated with DA decay and measured in coincidence with the two ejected Auger electrons has been carried out more recently for the case of Ar 2p photoionization [19].…”