Performance of a reflection-type polarizer by use of muscovite mica crystal in the soft x-ray region of 1keV

To develop the polarizer functioning in the soft x-ray region of 1keV, the polarization performance of muscovite mica has been investigated theoretically with a simulation code based on dynamical theory. As the result of calculation, muscovite mica is found to be a promising candidate as a reflection-type polarizer with the reflectivity for s polarization of 0.03 at approximately 0.9keV at the angle of incidence of 45°. In order to verify the polarization performance of muscovite mica experimentally, a symmetric Bragg reflection measurement of muscovite mica(002) was carried out using a linearly polarized undulator radiation. As a result, the maximum reflectivity for s polarization and the extinction ratio of muscovite mica were approximately 0.018 and 200 at 878eV, respectively. This result indicates that muscovite mica works as a practical polarizer in the soft x-ray region.