title: Polarization-dependent vacuum-ultraviolet reflectometry using elliptically polarized synchrotron radiation.
abstract: In the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the Berlin electron-storage ring BESSY II, a procedure has been developed to investigate the dependence of vacuum-ultraviolet reflection on polarization. It is based on characterizing the elliptically polarized synchrotron radiation at PTB's normal-incidence monochromator beamline for reflectometry by means of polarization-sensitive photodetectors. For this purpose, the polarization dependency in the detector responsivity was determined at a small, low, solid angle of acceptance for the synchrotron radiation, i.e., within the orbital plane of the storage ring where the degree of linear polarization is known to be almost 100%. Our method allows the polarization dependence of reflection samples to be measured with relative standard uncertainties ranging from 2.4% to 11% in the spectral range between 60 and 160 nm. The method has been applied to the optimization of polarizing mirrors at the Lyman-alpha wavelength of 121.6 nm.
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany. alexander.gottwald@ptb.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Gottwald
authors.forename: Françoise
authors.initials: F
authors.lastname: Bridou
authors.forename: Mireille
authors.initials: M
authors.lastname: Cuniot-Ponsard
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Desvignes
authors.forename: Simone
authors.initials: S
authors.lastname: Kroth
authors.forename: Udo
authors.initials: U
authors.lastname: Kroth
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Paustian
authors.forename: Mathias
authors.initials: M
authors.lastname: Richter
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schöppe
authors.forename: Reiner
authors.initials: R
authors.lastname: Thornagel