VERTICALLY FOCUSING DOUBLE MIRROR DEVICE (VF-2M) FOR THE ESRF BEAMLINE ID12A

A double mirror device (VF-2M) has been inserted in the monochromatic section of the ESRF beamline (BL) ID12A. It is aimed at refocusing the beam vertically very near the sample location and uses two identical bulk CVD SiC bendable mirrors in an antiparallel configuration. The be nders are actuated by two UHV compatible digital piezo devices with na nometric precision (Queensgate Instruments Ltd.). The first commission ing tests at BL ID12A revealed an excellent agreement between ray-trac ing predictions and experimental data. Vertical focus sizes as small a s 22 mu m FWHM have been obtained. The measured reflectivity is very c lose to calculated values, too.