We present the conceptual design of a dispersive X-ray Absorption Fine Structure (XAFS) beamline for MIRRORCLE,
a new compact laboratory X-ray source. This machine accelerates electrons up to 1,4,6 or 20MeV
(depending upon the model) in a ring and produces X-rays when the electrons collide onto a thin target. The
radiation emitted has a white spectrum due to both synchrotron and bremsstrahlung emission. A substantial
part of the electrons are recovered after collisions, and the emitted light has high flux, wide energy spectrum
and a large angular dispersion.
We have opted for a simple beamline design using a collimator, slits, a curved crystal, the sample environment
and a CCD. The beamline parameters (position of the mirror, ray of curvature, slit aperture, reflecting angle, etc.)
have been optimized by defining and improving a figure of merit. This optimization allows for room constraints
(distances among elements), mechanical constraints (minimum curvature radii available) and optical constraints.
Further ray tracing simulations using SHADOW3 have been performed to check all the theoretical results, refine
the final parameters, quantitative flux calculations and for simulating the image on the CCD camera.