New light on the Kr(4p55s2) Feshbach resonances: high-resolution electron scattering experiments and B-spline R-matrix calculations

T H Hoffmann (1, 2) , M.-W Ruf (1) , H Hotop (1) , O Zatsarinny (3) , K Bartschat (3) , M Allan (2, 3)

1 Fachbereich Physik [Kaiserslautern]
2 Department of Chemistry
3 Department of Physics and Astronomy [Des Moines]

8 In a joint experimental and theoretical effort, we carried out a detailed study of electron scattering from Kr atoms in the energy range of the low-lying Kr − (4p 5 5s 2) Feshbach resonances. Absolute angle-differential cross sections for elastic electron scattering were measured over the energy range 9.3−10.3 eV with an energy width of about 13 meV at scattering angles between 10 @BULLET and 180 @BULLET. Using several sets of elastic scattering phase shifts, a detailed analysis of the sharp Kr − (4p 5 5s 2 2 P 3/2) resonance was carried out, resulting in a resonance width of Γ 3/2 = 3.6(2) meV. By direct comparison with the position of the Ar − (3p 5 4s 2 2 P 3/2) resonance, the energy for the Kr − (4p 5 5s 2 2 P 3/2) resonance was determined as E 3/2 = 9.489(3) eV. A Fano-type fit of the higher-lying Kr − (4p 5 5s 2 2 P 1/2) resonance yielded the resonance parameters Γ 1/2 = 33(5) meV and E 1/2 = 10.126(4) eV. In order to obtain additional insight, B-spline R-matrix calculations were performed for both the elastic and the inelastic cross sections above the threshold for 4p 5 5s excitation. They provide the total and angle differential cross sections for excitation of long-lived and short lived levels of the 4p 5 5s configuration in Kr and branching ratios for the decay of the Kr − (4p 5 5s 2 2 P 1/2) resonance into the three available exit channels. The results are compared with selected experimental data.

Mots clés: Physical Sciences

T H Hoffmann, M.-W Ruf, H Hotop, O Zatsarinny, K Bartschat, et al.. New light on the Kr(4p55s2) Feshbach resonances: high-resolution electron scattering experiments and B-spline R-matrix calculations. Journal of Physics B: Atomic, Molecular and Optical Physics, 2010, 43 (8), pp.85206. ⟨10.1088/0953-4075/43/8/085206⟩. ⟨hal-00569907⟩