M. Togawa,
S. Kuhn,
C. Shah,
P. Amaro,
R. Steinbrügge,
J. Stierhof,
N. Hell,
M. Rosner,
K. Fujii,
M. Bissinger,
R. Ballhausen,
M. Hoesch,
J. Seltmann,
S. Park,
F. Grilo,
F. S. Porter,
J. P. Santos,
M. Chung,
T. Stöhlker,
J. Wilms,
T. Pfeifer,
G. V. Brown,
M. A. Leutenegger,
S. Bernitt,
and J. R. C. Lopez-Urrutia
Observation of strong two-electron–one-photon transitions in few-electron ions
Phys. Rev. A, 102 :052831 (November 2020)
Observation of strong two-electron–one-photon transitions in few-electron ions
Phys. Rev. A, 102 :052831 (November 2020)
Abstract:
We resonantly excite the K series of O5+ and O6+ up to principal quantum number n=11 with monochromatic x rays, producing K-shell holes, and observe their relaxation by soft-x-ray emission. Some photoabsorption resonances of O5+ reveal strong two-electron–one-photon (TEOP) transitions. We find that for the [(1s2s)15p3/2]3/2;1/2 states, TEOP relaxation is by far stronger than the radiative decay and competes with the usually much faster Auger decay path. This enhanced TEOP decay arises from a strong correlation with the near-degenerate upper states [(1s2p3/2)14s]3/2;1/2 of a Li-like satellite blend of the He-like Kα transition. Even in three-electron systems, TEOP transitions can play a dominant role, and the present results should guide further research on the ubiquitous and abundant many-electron ions where electronic energy degeneracies are far more common and configuration mixing is stronger.