DOUBLE-ELECTRON EXCITATION CHANNELS AT THE BR K-EDGE OF HBR AND BR2

We report the direct measurement by x-ray-absorption spectroscopy of the complete spectrum of multielectron excitations at the Br- K edge. Measurements of crystalline tetramethylammonium bromide were made at 30 K and room temperature. The latter spectrum has been found to be largely dominated by the opening of multielectron excitation channels, thus providing a very good model of the Br- atomic background which can be used in the analysis of ionic bromine compounds. The complete sequence of multielectron transitions has been clearly identified and compared with theoretical determinations. A direct experimental determination of the [1s4p] double-electron excitation channel has been performed at the Br- K edge.© 2001 The American Physical Societ