Tiny diamonds prove an excellent material for accelerator
components

When it comes to producing high-quality electron beams
like those found in state-of-the-art scientific equipment like
free-electron lasers, ultrafast electron diffraction and imaging
and wakefield accelerators, scientists have looked to photocathode
technology as a way to convert light to electrons. These tools give
researchers a way to more deeply penetrate into materials and
atomic structure and behavior under real-world
conditions.