ENERGY DISPERSIVE EXAFS

Energy dispersive EXAFS (EDE) is a technique for recording X-ray Absorption Fine Structure in which the whole spectrum of interest is obtained at the same time so allowing time-resolved experiments to be performed.

A horizontal fan of polychromatic radiation is focused onto the sample which subsequently diverges onto a position sensitive detector behind the sample. The X-ray energy varies across the width of the fan so all energies needed to make the EXAFS spectrum are passed through the sample simultaneously, and the data can be obtained in milliseconds. The geometry of the experiment means that only transmission experiments can be done, and hence the technique is restricted to fairly concentrated systems. The method is mostly used for catalysis and chemical reactions. While time resolution is very good, the time taken to set up the experiment can be very long and it is a relatively demanding technique.

station 9.3