BEAR an experimental station for optical characterization in VIS -Soft X range

BEAR (http://www.elettra.trieste.it/experiments/beamlines/bear/index.html) is a bending magnet synchrotron beamline (Elettra-Trieste). Experimental station is to study performances (specular reflectivity, diffuse scattering, polarimetry) of devices (multilayer mirrors-ML, gratings, coatings, etc) in the VIS-soft X region (3 - 1500 eV; 0.83-413 nm). Polarization from linear (s , p) to elliptical (left-right). Light spot features E/ΔE ~ 5000 (N K-edge), spectral purity < 1%, max divergence 20 mrad, cross section tipical 30×400 (max) v x h um x um. Highly flexible incidence and collection geometries with angle resolved detectors (diodes, channeltron, electron energy analyzer) covering whole solid angle. Specular (theta-2theta, energy scan) and (rocking, ω-scan) diffuse reflectivity available. Photoemission (UPS-XPS) is simultaneously made available. Other available characterization tools include Auger and fluorescence emission and X-ray excited luminescence. Examples will be given, including reflectivity, stability and phase shift for reflectivity of ML, buried interfaces analysis correlated with ML performance, thin films and materials optical constants.