Angle-resolved study of the Auger electron cascades following the 1s→3p photoexcitation of Ne

Abstract

The spectra of Auger electrons are measured for the cascade decay of the photoexcited 1s −1 3p resonance in Ne. Angular distributions of the Auger electrons for the prominent peaks of the spectra are determined. It is shown that in the first step of the cascade which corresponds to the spectator (shake-modified spectator) transitions 1s −1 3p → 2s −1 2p −1 3p(4p) and 1s −1 3p → 2s −2 3p(4p) the electrons are emitted almost isotropically. In contrast, the majority of the secondstep transitions 2s −1 2p −1 3p(4p) → 2p −2 and 2s −2 3p(4p) → 2s −1 2p −1 shows strong anisotropy. A qualitative explanation of the observed results is given.

Multireference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atom

“…Here we compared all these approaches with respect to their ability to reproduce the experimental [65,66] as well as theoretical AES obtained at the fully relativistic MCDF level [64]. We showed that the Auger energies obtained with a Rydberg basis set and an active space allowing single electron excitations into the 3s, 3p, 4s, and 4p orbitals are generally in good agreement with the theoretical reference.…”

“…Hence, in Fig. 4 the spectra obtained with the QC models I-III and the r −1 • V JX f (r) • SO approach are compared against experimental data taken from Kivimäki et al [65], for the d region (a), and Yoshida et al [66], for the s and p regions (b). The spectra have been shifted by −5.35 eV, −4.75 eV, and −5.18 eV for QC models I, II, and III to align the peaks at 811.5 eV.…”

“…Panel (a) shows that the agreement between the experimental and the theoretical spectra is fairly good. In fact, the relative energetic positions and intensities of the To account for the different lineshapes of the experimental spectra that have been digitalized from [65], panel (a), and [66] in panel (b), broadening with a Gaussian FWHM of 0.25 eV and 0.77 eV was used in panels (a) and (b), respectively. Further, the spectra have been normalized individually to the peaks at 811.5 eV (a) and 776 eV (b).…”

“…Although the ultimate goal is to investigate molecules, this proof-of-concept contribution focuses on the simulation of the prototypical neon 1s −1 3p Auger Electron Spectrum (AES) to calibrate the approach, since highly accurate reference data are available for both theory [64] and experiment [65][66][67][68]. Special attention is paid to the representation of the radial continuum waves, which is investigated herein by a thorough test of different approximations.…”

“…Comparison of experimental and theoretical neon 1s −1 3p AES obtained based on the QC schemes I -III with the r −1 • V JX f (r) • SO method. The spectra obtained with QC I, II, and III have been shifted by −5.35 eV, −4.75 eV, and −5.18 eV, respectively, to align the peak at 811.5 eV with the experimental data in panel (a).To account for the different lineshapes of the experimental spectra that have been digitalized from[65], panel (a), and[66] in panel (b), broadening with a Gaussian FWHM of 0.25 eV and 0.77 eV was used in panels (a) and (b), respectively. Further, the spectra have been normalized individually to the peaks at 811.5 eV (a) and 776 eV (b).…”