A Facility for the Measurement of the Soft X-ray Reflectivity Spectrum of XUV and Soft X-ray Mirrors

Abstract

The spectrally resolved reflectivity coefficient of multilayer mirrors is measured in the EUV-soft X-ray spectral region. A laser produced plasma (LPP) acts as a bright source of continuous spectrum radiation, and it is used to light the multilayer mirror under test. The reflected rays are collected by a grazing incidence toroidal mirror and focused in the entrance slit of a grazing incidence spectrograph, where the spectrum is detected. The ratio of such spectrum with that obtained with the direct collection of the LPP spectrum, corrected for the higher diffraction orders contributions, is the spectrum of the absolute reflectivity coefficient for the mirror[1].