We have constructed an X-ray phase plate to produce linearly and circularly polarized X-rays at discrete energies between 20 keV and 88 keV. The plate is a monolithic two-crystal design, constructed from germanium. We have measured the degree of circular polarization at 65 keV to be 90%±4%, which is significantly better than that produced by silicon phase plates. This radiation was used to measure the magnetic Compton profile for Fe, which was found to be in good agreement with theory and previous work. The underlying X-ray optics and the characterization of the device between 62 keV and 93 keV at the Cornell High Energy Synchrotron Source are presented. © 1994.
Yahnke, C. J., Srajer, G., Haeffner, D. R., Mills, D. M., & Assoufid, L. (1994). Germanium X-ray phase plates for the production of circularly polarized X-rays. Nuclear Inst. and Methods in Physics Research, A, 347(1–3), 128–133. https://doi.org/10.1016/0168-9002(94)91868-6