The detection of vacuum birefringence induced by a large electric field requires an extremely high polarization purity in the order of 10-11 at a photon energy of 12 keV. With present x-ray polarizers based on silicon channel-cut crystals using multiple consecutive crystal reflections a polarization purity of 2.4 ·10-10 at a photon energy of 6.44 keV can be reached [1].

I report about the idea to improve the polarization purity of present x-ray polarimeter by using synthetic diamond crystals. Such a polarimeter consists of a polarizer and analyzer, each based on two parallel diamond crystals with a Bragg angle close to 45°. I show first results from an experiment performed at the European Synchrotron Radiation Facility (ESRF) using the diamond (400) Bragg reflection and synchrotron undulator radiation at an x-ray energy of 9.84 keV to polarize x-rays.


[1] B. Marx, K. S. Schulze, I. Uschmann, T. Kämpfer, R. Lötzsch, O. Wehrhan, W. Wagner, C. Detlefs, T. Roth, J. Härtwig, E. Förster, T. Stöhlker and G. G. Paulus, Phys. Rev. Lett. 110, 254801 (2013)

Seminarraum HI-Jena, Fröbelstieg 3
Datum (Start der Veranstaltung)