Detailed analysis of shake structures in theKLLAuger spectrum ofH2S

Abstract

Shake processes of different origin are identified in the KLL Auger spectrum of H 2 S with unprecedented detail. The KLL Auger spectrum is presented together with the S 1s −1 photoelectron spectrum including the S 1s −1 V −1 nλ and S 1s −1 2p −1 nλ shake-up satellites with V −1 and nλ indicating a hole in the valence shell and an unoccupied molecular orbital, respectively. By using different photon energies between 2476 and 4150 eV to record the KLL Auger spectra two different shake-up processes responsible for the satellite lines are identified. The first process is a shake-up during the Auger decay of the S 1s −1 core hole and can be described by S 1s −1 → 2p −2 V −1 nλ. The second process is the Auger decay of the shake-up satellite in the ionization process leading to S 1s −1 V −1 nλ → 2p −2 V −1 nλ transitions. By combining the results of photoelectron and Auger spectra the involved V −1 nλ levels are assigned.

Effects of the molecular potential on coexcitations of valence electrons in the K -shell photoeffect of 3p and 4p elements

“…The MEPEs are treated as a two-step process, in sudden approximation. Such calculation is conventionally used for deeper coexcitations, but it agrees surprisingly well with satellite energies in a recently measured photoelectron spectrum of H 2 S [55]. It also describes well the cross section [1s3p] in Ar [56], agreeing perfectly with the latest many-body perturbation results [57].…”

“…The dominance of coexcitation to the atomic orbitals is found also in an emission-spectroscopy experiment on H 2 S [55]. The experimental and theoretical probabilities for transition into the [1s2p]σ * ε p states in H 2 O [62] are given in the range of 2.6%-3.4%, comparable to our results for homologous hydrides H 2 S (3.4% ± 1.0%) and H 2 Se (3.9% ± 1.0%).…”

KL double core hole pre-edge states of HCl

“…For H 2 S, the 2p À2 V À1 higher-n Ryd 1 states are found to be 31.5 eV above the corresponding 2p À2 states. 30 From this we conclude that the ionization potential of the valence orbitals in the presence of two core holes amounts at least 35 eV. An upper limit can be given using Argon and the Z+2 approximation.…”

Detailed assignment of normal and resonant Auger spectra of Xe near the L edges

“…These values are approximately 12 eV above the ionization potentials of the L 3 ,L 2 , and L 1 ionization thresholds and guarantee that in the Auger spectra only shakes during the Auger process can be observed while Auger decays of shake-up or shakeoff states during the photoionization process are absent. As recently shown for H 2 S, shake processes occurring during the ionization and the decay process are present well above threshold, rendering the assignment more complicated [17]. The resonant Auger spectra were recorded at different photon energies directly below the L 1 ,L 2 , and L 3 threshold by using kinetic-energy windows of 45-65 eV around the most intense 2s −1 → 3d −2 6p and 2p −1 → 3d −2 5d transitions.…”

“…The Auger transitions at a binding energy of 791 and 803 eV visible in spectra (a-c) are also not reproduced by theory. Since the Auger spectra are measured at excitation energies below the first satellites in the photoelectron spectrum, these spectral features can be assigned to 5p → 6p shake-up transitions during the Auger decay [17]. These assignments are based on the fact that the kinetic energies of these two lines are approximately 23 eV below those of the main lines at binding energies of 768 and 780 eV, which agrees well with the excitation energies of 22-25 eV for the 5p 6 → 5p 5 6p transition in the Z + 2 atom Ba III [20].…”