Multilayer optics for intense synchrotron x-ray beams: Recent results on their performance

Abstract

Present-day synchrotron x-ray beams are very demanding in terms of thermal, mechanical, and radiation stability of any optical element to be inserted in the beam. A set of multilayers was recently exposed and could resist to an x-ray power density in excess of 7.5 W/mm2, which is comparable to the one expected for the multilayers to be used at ESRF. Such a power density was obtained by setting the multilayers at a grazing angle of about 2° in a focused wiggler beam of 4.6 keV critical energy. The specimen, W/B4C and W/Si multilayers, were cooled either at room temperature or down to liquid nitrogen temperature during an 8–16 h exposure time.