ABSTRACT
In the x-ray emission process, a core hole is fi rst created (say, in core level c) by incident x-ray or electron beam, and then a valence electron or a core electron in the core level higher than c makes a radiative transition to the core level c by emitting an x-ray photon. When the incident x-ray energy resonates with the excitation threshold of the core electron, this x-ray emission is called “resonant x-ray emission” (or resonant x-ray Raman scattering), while if the incident energy is large enough to excite the core electron to a high energy continuum well above the excitation threshold, it is called “normal x-ray emission” (or ordinary x-ray emission, or x-ray fl uorescence).
