Novel diamond X-ray crystal optics for synchrotrons and X-ray free-electron lasers

The most common applications of diamond crystals in X-ray optics are high-heat-load monochromators for synchrotron beamlines and phase retarders for polarization control. Here, less common applications of diamond at the frontier of X-ray crystal optics are reviewed and summarized. These include a sub-meV-bandwidth X-ray monochromator with high spectral efficiency [1] and all-diamond optical assemblies for a beam-multiplexing double-crystal monochromator at the Linac Coherent Light Source [2]. Also, novel applications for the realization of fully coherent hard X-ray sources are discussed, such as, diamond crystal optics for self-seeding of hard X-rays in the Linac Coherent Light Source [3,4] and Bragg mirrors for the highly anticipated X-ray free-electron laser oscillator [5,6]. These examples present diamond as a material for the next generation of X-ray optics, optics which can provide unique characteristics and capabilities to modern X-ray sources. In addition, details of practical importance on fabrication and characterization methods of diamond crystals with the suitable quality are presented. •Comprehensive review of novel diamond crystal optics for synchrotrons and XFELs•Details of practical importance on fabrication and characterization methods of diamond crystals with suitable quality•New insights on further development of diamond technology for applications in X-ray optics