First Observation of Two-Electron One-Photon Transitions in Single-Photon<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi></mml:math>-Shell Double Ionization

Abstract

Experimental evidence for the correlated two-electron one-photon transitions (1s(-2)→2s(-1)2p(-1)) following single-photon K-shell double ionization is reported. The double K-shell vacancy states in solid Mg, Al, and Si were produced by means of monochromatized synchrotron radiation, and the two-electron one-photon radiative transitions were observed by using a wavelength dispersive spectrometer. The two-electron one-photon transition energies and the branching ratios of the radiative one-electron to two-electron transitions were determined and compared to available perturbation theory predictions and configuration interaction calculations.