Multielectron photoexcitations in x-ray-absorption spectra of $4p$ elements

By removing the structural x-ray-absorption fine-structure signal from K-edge absorption spectra of $4p$ elements from Ga to Br in chalcogenide glasses and other samples, the pure atomic absorption is recovered. Its main components are shake-up and shake-off channels of the $[1s3p]$ and $[1s3d]$ group. The $[1s3p]4p$ shake-up channel is observed to close off along the series as the $4p$ shell is progressively filled.