X-ray polarization splitting with the Baronova-Stepanenko spectropolarimeter

X-rays scattered over 90° in two mutually perpendicular directions are split into their linearly polarized components. Recently Baronova and Stepanenko realized that the three orthogonal X-ray paths are consistent with Bragg reflection over 90° when the reflecting crystal planes are under 120° with each other. These planes exist in crystals with three-fold symmetry, notably hexagonal crystals such as quartz, and in cubic crystals such as silicon and germanium. X-ray spectropolarimetry with polarization-splitting crystals can be done with various X-ray lines that are useful in diagnostics of Fast Ignition plasmas.