Advancing beam shaping from visible light to X-rays for synchrotron applications.

Customized beam shaping has a wide range of applications from visible light to hard X-rays. While laser beam shaping has matured over recent decades, enabling breakthroughs in optical communication, optical tweezers, and advanced microscopy, extending these techniques to high-brightness X-ray sources could significantly enhance synchrotron applications such as macromolecular crystallography, spectroscopy, and high-resolution imaging. However, X-ray beam shaping remains challenging due to limitations in the available optics and the finite phase-space of synchrotron sources. We introduce a novel method that exploits the monochromatic angular spectrum of undulator radiation combined with the compound refractive lenses (CRLs) to produce a variable circular focal spot with a top-hat intensity profile. By fine-tuning the undulator gap and monochromator settings, this approach enables dynamic control of the spatial beam profile while preserving continuous energy tunability within the limits imposed by the optical configuration and experimental conditions. This technique delivers flexible beam shaping without requiring complex new optical designs, construction, or operational overhead. This method has been successfully demonstrated on a macromolecular crystallography beamline at the Diamond Light Source (DLS), confirming its practicality, adaptability, and potential for widespread adoption in synchrotron-based research.