High-flux, moderate-bandwidth, high-energy X-rays from lapped Si(111) crystals in a double-crystal monochromator

Lapping the surfaces of Si(111) crystals in a double-crystal monochromator significantly increases the intensity of high-energy X-ray beams. Systematic characterization using 100 keV X-rays shows that the total flux increases by factors of 7-11 relative to polished crystals. The resulting energy bandwidth (0.12-0.21%) remains substantially narrower than that of multilayer optics. These characteristics provide a useful compromise between spectral selectivity and beam intensity, enabling practical X-ray measurements that are difficult to achieve with either perfect-crystal monochromators or multilayer optics alone. Demonstrations of imaging, powder diffraction, and incoherent micro-focusing further highlight the practical utility of the resulting beams in applications where high photon statistics are prioritized. These results demonstrate that lapped Si crystals provide a robust and cost-effective approach to generating high-flux, moderate-bandwidth high-energy X-ray beams.