High purity x-ray polarimetry with single-crystal diamonds

Abstract

We report on the use of synthetic single-crystal diamonds for high purity x-ray polarimetry to improve the polarization purity of present-day x-ray polarimeters. The polarimeter setup consists of a polarizer and an analyzer, each based on two parallel diamond crystals used at a Bragg angle close to 45 •. The experiment was performed using one (400) Bragg reflection on each diamond crystal and synchrotron undulator radiation at an x-ray energy of 9838.75 eV. A polarization purity of 8.9×10 −10 was measured at the European Synchrotron Radiation Facility (ESRF), which is the best value reported for two-reflection polarizer/analyzer setups. This result is encouraging and a first step to improve the resolution of x-ray polarimeters further by using diamond crystal polarizers and analyzers with four or six consecutive reflections.

Diamond channel-cut crystals for high-heat-load beam-multiplexing narrow-band X-ray monochromators

“…Along with applications as monochromators, other applications of the diamond channel-cut crystals are anticipated. In particular, because diamond crystals feature very high X-ray reflectivity, they can be used as efficient four-bounce or sixbounce channel-cut polarizers and analyzers to achieve a very high degree of X-ray polarization purity (Bernhardt et al, 2016).…”

Diamond Channel-Cut Crystals for High-Heat-Load, Beam-Multiplexing, Narrow-Band X-ray Monochromators

“…Along with applications as monochromators, other applications of the diamond channel-cut crystals are anticipated. In particular, because diamond crystals feature very high x-ray reflectivity, they can be used as efficient four-bounce or six-bounce channel-cut polarizers and analyzers to achieve a very high degree of x-ray polarization purity [47].…”

Expanding Nuclear Physics Horizons with the Gamma Factory

“…In addition, in the recent years, Bragg scattering was successfully used for high–precision polarization measurements in the keV energy range. [ 424–426 ]…”

“…[ 451–455 ] For X‐rays of $$\omega \simeq {\cal O}(10)\,{\rm keV}$$ the possibility of measuring such tiny ellipticities has been demonstrated experimentally. [ 424–426 ] While these X‐ray techniques cannot be used at 400 MeV, in the latter parameter regime pair‐production polarimetry may be used. [ 430,431 ] See refs.…”