Proposal for a femtosecond X-ray detector

A scheme for time-resolved X-ray detection with potentially better than 10 fs time resolution is proposed. The central idea is to use intense fs-laser pulses to depopulate the valence band of a semiconductor and thus switch the absorption of X-rays, monochromatized to just below an absorption edge of the material. The effect can be used as a fast shutter and as a fast detector by recording secondary processes such as X-ray fluorescence or resonant Raman scattering.