Linear polarization measurements with a new soft X-ray polarimeter and ellipsometer at a bending magnet beamline of a compact storage ring

Imazono, Takashi; Sano, Kazuo*; Suzuki, Yoji; Kawachi, Tetsuya; Koike, Masato

Linear polarization measurements were carried out using a newly developed soft X-ray polarimeter and ellipsometer (SXPE) for complete polarization analysis at a soft X-ray beamline (BL-11) of the SR Center, Ritsumeikan University, Japan. A Mo/Si multilayer mirror was deposited on the surface of a Si(111) substrate by an ion beam sputtering method. It was cut into two pieces which were then used as reflection-type polarizers. When the incident wavelength was scanned from 12.4 nm to 14.8 nm by a Monk-Gillieson type varied-line-spacing grating monochromator of the BL-11, the angles of incidence of both the Mo/Si multilayer polarizers in the SXPE were also varied from 37.5 to 52.3. The polarizances depended strongly on the wavelength, and the best performance of over 99% was obtained in the vicinity of 14 nm. Using these polarizers, we assessed that the degree of linear polarization of the BL-11 was almost constant at 85-88% in the measured wavelength range.