Deep-core photoionization of krypton atoms below and above the $1s$ ionization threshold

Electronic relaxation of atomic Kr below and above the $1s$ ionization threshold is investigated experimentally using hard x-ray photoelectron spectroscopy. The experimental results are interpreted with the aid of relativistic Dirac-Fock calculations. The $1s$ orbital core-hole lifetime is extracted and the satellite's structures accompanying the photoelectron main line are assigned. Auger spectra recorded below and above the $K$ edge are also investigated. In particular, the Auger cascade originating from vacancies of different origin in the $L$ shell is analyzed in great detail. Competition between radiative $KL$ versus nonradiative $KLL$ Auger emission is emphasized.

Figure 1

Experimental and theoretical Kr $1s$ photoelectron spectra. The $1s^{-1}4p^{-1}$ and $1s^{-1}4s^{-1}$ double-ionization thresholds are indicated by vertical lines.

Figure 2

Experimental and calculated Auger electron spectra (a) above and (b) below the $1s$ ionization threshold of Kr at photon energies of 16.5 and 13.0 keV. The spectra are normalized to the peak at 1460 eV having height of 100. ${\mathrm{Kr}}_{CK}^{2+}$ and ${\mathrm{Kr}}_{KL}^{2+}$ denote dicationic Kr states populated by $LLX$ Coster-Kronig Auger decay and $KLX$ ($X=L,M,N$) Auger decay, respectively.

Figure 3

Partial ${\mathrm{Kr}}^{1+}\to {\mathrm{Kr}}^{2+}$ contribution to total Auger spectrum (a) above and (b) below the $1s$ ionization threshold. The different colors and patterns in the lower part of each panel indicate the contribution of transitions to individual final-state configurations.

Figure 4

Partial ${\mathrm{Kr}}_{CK}^{2+}\to {\mathrm{Kr}}^{3+}$ contribution to the Auger spectrum (a) above and (b) below the $1s$ ionization threshold. The different colors and patterns in the lower part of each panel indicate the contribution of transitions to individual final-state configurations.

Figure 5

Partial ${\mathrm{Kr}}_{KL}^{2+}\to {\mathrm{Kr}}^{3+}$ contribution to the total Auger spectrum after $1s$ ionization. The different colors and patterns in the lower part of each panel indicate the contributions of transitions to individual final-state configurations.

Figure 6

Partial ${\mathrm{Kr}}^{3+}\to {\mathrm{Kr}}^{4+}$ contribution to the total Auger spectrum after 1s ionization. The different colors and patterns in the lower part indicate the contributions of transitions to individual final-state configurations.