Optimisation of a compact optical system for the beamtransport at the x-ray fluorescence beamline at Elettra for experiments with small spots

This paper reports a simplified and compact mechanical scheme designed for providing alternatively high flux or high spectral resolution from a monochromator for the 2 - 14 keV X-ray range in a stationary spot at a sample. The example case treats a bending magnet source at the Elettra storage ring. The properties of the continuously tunable monochromatic beam are adapted for a variety of experimental techniques, which include also the need to operate the sample in the total reflection regime, i.e. at angles of grazing incidence smaller than the critical angle of the sample material. The positional stability of the monochromatised beam during tuning was the major concern in the design of the monochromator.