New Window Resonances in the Potassium 3sPhotoabsorption Spectrum

Abstract

The photoion spectrum of atomic potassium was measured over the 3s → np excitation region with the photoion time-of-flight method and monochromatized synchrotron radiation. An unusual spectrum with paired windows structure was found instead of a simple regular Rydberg series. Such subsidiary windows have not been observed in the 3s → np resonances of Ar, which has a closed outer shell. Based on Dirac-Fock calculations, the dual window structure at 36.7 eV and at 37.4 eV was assigned to the 3s −1 3p 6 4s4p resonance. The line shape can be fitted by Fano's formula and the Fano parameters were obtained.

Stimulated Raman adiabatic passage into continuum

“…The Stark shifts are assumed zero because, as we have verified, they do not affect significantly the ionization signal. For the Fano parameter we have chosen three values: q = 1, q = 3, q = 6, which are close to the experimental values for LICS in sodium (q = 3.7) [17], helium (q = 0.73) [18], and hydrogen atoms (q = −5.9) [5], for electric-field mixing in rubidium (q = 3.3) [19], and for configuration mixing in potassium (q = 1) [20], rubidium (q = 0.1 − 0.3) [21], and cesium (q ≈ 0.43) [21]. Figure 5 shows contour plots of the ionization signal as a function of the center of the control pulse τ c and the peak control ionization rate Γ c0 for different values of the Fano parameter q and the irreversible loss rate Γ from state ψ 2 .…”

Time dependent aspects in the ionizations following atomic photoexcitations

“…2, we illustrate the experimental photoion spectra of potassium 3s-photoionization together with the result of theoretical calculation, which were performed by Koide et al [2]. They observed a doubly dipped nature in the 3s ?…”

“…Apparent double well structure of 3s ? 4p excitation in potassium singly charged ion yield spectrum near 37 eV of incident photon energies [2]. Dotted curve is K + ion yield spectrum.…”

“…If we observe those energy differences in a time domain, we may find quantum beats [1]. If autoionization or Auger process take place during these quantum beats, electrons will carry out the information of the beats [2,3]. When atomic or atomic ionic autoionization or Auger process take place under the presence of a slowly receding photoelectron, the autoionizing or Auger electron will carry out the information of the receding electrons.…”

“…Autoionization of photon-impact induced doubly or inner-shell excited atomic states may sometimes create multiplet states in residual ions. In atomic species with moderate atomic numbers, the multiplet nature is typically caused by spin-orbit interactions in ionic open-shell electrons [2,3]. In these systems, the open-shell undergoes precessions between different total angular momentum states of ions, and its cycle time gives us a good clock to measure the lifetime of the autoionizing states.…”