Transition metal coatings for reflection polarimeters in the 50-100 eV region

Spectroscopic experiments requiring the knowledge of the specific state of light polarization for synchrotron radiation, high-order laser harmonics and free-electron lasers are increasing in the recent years. Correspondingly, there has been an increasing demand for systems to measure polarization in the extreme ultraviolet (XUV) and soft X-ray (SX) regions. Polarization can be measured at a specific wavelength through the use of polarizers based on multilayer coatings, that are almost routinely available. The measurement on a broad band requires to operate at grazing incidence with metallic coatings. It is here presented the design and performances of a reflection polarimeter to be used in the 50-100 eV region with transition metal-coated optics. With respect to standard polarimeters, based on gold-coated optics, the presented coatings gives higher flux and higher contrast between phase and reflectivity responses for s- and p-polarized light. The optical and mechanical design of the polarimeter and the estimated throughput are discussed.