A New soft X-ray polarimeter and ellipsometer at BL-11

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

A novel apparatus for polarimetric and ellipsometric measurements for the complete polarization analysis in the soft X-ray (SX) region, which is based on the rotating-analyzer ellipsometry by using six independently movable drive shafts, has been designed, constructed, and installed in BL-11. Linear polarization measurement has been demonstrated using two identical Mo/Si multilayer polarizers. The incident wavelength was scanned from 12.4 nm to 14.8 nm by a VLS-PGM of BL-11, and the angles of incidence of both polarizers were also varied from 37.5 to 52.3. The best performance of polarizers has been determined to be over 99% at 13.9 nm, and the degree of linear polarization has been assessed to be 85-88% in the measured wavelength range for the first time since the completion of the beamline. This means that BL-11 is upgraded as the comprehensive evaluation beamline for optical elements including polarizing elements for use in the SX region.