Benchmark Angle-Differential Cross-Section Ratios for Excitation of the 4p5s Configuration in Krypton

Abstract

Benchmark intensity ratio measurements of the energy loss lines of krypton for excitation of the 4p61S0→4p55s[3/2]2, 4p55s[3/2]1, 4p55s′[1/2]0, and 4p55s′[1/2]1 transitions are reported, these being the lowest electronic excitations for krypton. The importance of these ratios as stringent tests of theoretical electron scattering models for the noble gases is discussed, as well as the role of spin-exchange and direct processes regarding the angular dependence of these ratios. The experimental data are compared with predictions from fully-relativistic B-spline R-matrix (close-coupling) calculations.

Electron-impact excitation of the 5$$\varvec{^2\textbf{S}_{1/2} \rightarrow 5^2\textbf{P}_{1/2}}$$ and 5$$\varvec{^2\textbf{P}_{3/2}}$$ transitions in rubidium by 40 eV electrons: theory and experiment

“…These ratios can be very sensitive to details of the theoretical model. For two examples, see the recent studies on the noble gases Kr [34] and Xe [35], where the fine-structure is easier to resolve in the electronic channel than in the alkalis Fig. 4 DCS for the (5s) 2 S 1/2 → (5p) 2 P transition with unresolved fine-structure, as obtained in various DBSR and BPRM models described in the text.…”

Electron scattering processes: fundamentals, challenges, advances, and opportunities

“…Here we focus on some examples of measurements and calculations of electron impact excitation cross-sections of rare gas (atomic) targets. In the case of krypton, the excitation of the Kr {1} 4p 6 1 S 0 → 4p 5 5s[3/2] 2 , {2} 4p 6 1 S 0 → 4p 5 5s[3/2] 1 , {3} 4p 6 1 S 0 → 4p 5 5s′[1/2] 0 , and {4} 4p 6 1 S 0 → 4p 5 5s ′[1/2] 1 transitions were re-measured and reported recently [63]. The particular focus of this work was on the ratios of the scattering electron impact excitation DCSs (σ) for these excitations, which were proportional to the electron scattering intensities in the energy loss spectra.…”

“…The particular focus of this work was on the ratios of the scattering electron impact excitation DCSs (σ) for these excitations, which were proportional to the electron scattering intensities in the energy loss spectra. These ratios have been defined as r = σ{1}/σ{3}, r′ = σ{2}/σ{4}, r′′ = σ{1}/σ{2}, and r′′ = σ{3}/σ{4} (see [63] for details). The states {1} and {3} are well LS-coupled 3 P 2 and 3 P 0 states that can be only excited by spin-exchange through electron exchange, by spin-orbit coupling in the target, or via the continuum incident electron.…”

“…The states {1} and {3} are well LS-coupled 3 P 2 and 3 P 0 states that can be only excited by spin-exchange through electron exchange, by spin-orbit coupling in the target, or via the continuum incident electron. The ratios were determined more precisely in the recent work and provided information on dynamic effects [63]. Here, only the r′′ ratio is discussed for brevity, as this ratio shows the fewest uncertainties.…”

“…Here, only the r′′ ratio is discussed for brevity, as this ratio shows the fewest uncertainties. Full discussions are given in [63], to which the reader is urged to refer. In Fig.…”