A vacuum soft X-ray reflectometer for the characterization of multilayer mirrors by synchrotron radiation at DA Phi NE

High-reflectivity multilayers are required in many soft X-ray researches, from nowadays Synchrotron Radiation (SR) to future Free Electron Laser (FEL) optics. These synthetic reflectors are capable of working at near-normal incidence covering the lower X energy range not accessible by crystal diffraction. Recently, the deposition of such devices has progressed at INFN Lcgnaro Laboratories (LNL), giving robust Si/Mo mirror devices and first Ni/Ti and Ni/TiO2 multilayers. To test these new optics, at INFN Frascati Laboratories (LNF) a new vacuum compatible reflectometer has been assembled and commissioned in 2005. The final system is a theta-2 theta diffractometer in vacuum environment, endowed with high angular resolution and repeatability and absolute detectors. A direct characterization of multilayer performances have been accomplished by SR from a wiggler source at DA Phi NE. Results on characterization of the vacuum reflectometer and on the new Ni-Ti based multilayers are presented.