Abstract
A novel X-ray polarimeter has been constructed from two-fold Bragg-reflecting channel-cut germanium crystals. The well-known 333 Bragg reflection of copper Kx 1 radiation was used. In addition, elliptically polarized X-rays were produced with a 220 Bragg-reflecting silicon-crystal phase plate placed between the germanium polarizer and analyser. In a series of experiments the optical properties of various non-diffracting materials were measured. Upper bounds were determined for linear dichroism in sheet polaroid and for circular dichroism in quartz. No evidence has so far been obtained for birefringence in calcite but significant indication of optical rotary power was found in quartz. All of these optical effects have been known for some time in diffracting crystals for which case they can be described by the conventional dynamical diffraction theory.