Protective coatings are common for many things in daily life that see a lot of use: we coat wood floors with finish; apply Teflon to the paint on cars; even use diamond coatings on medical devices. Protective coatings are also essential in many demanding research and industrial applications.

Now, researchers at Los Alamos National Laboratory have developed and tested an atomically thin graphene coating for next-generation, electron-beam accelerator equipment — perhaps the most challenging technical application of the technology, the success of which bears out the potential for «Atomic Armor» in a range of applications.

«Accelerators are important tools for addressing some of the grand challenges faced by humanity,» said Hisato Yamaguchi, member of the Sigma-2 group at the Laboratory. «Those challenges include the quest for sustainable energy, continued scaling of computational power, detection and mitigation of pathogens, and study of the structure and dynamics of the building blocks of life. And those challenges all require the ability to access, observe and control matter on the frontier timescale of electronic motion and the spatial scale of atomic bonds.»

The challenge of photocathodes

Current electron-beam accelerators generally use thermionic emission — the heating of material to release electrons. The next generation of accelerators will generate electron sources from photons, using photocathodes — materials that can convert photons to free electrons and thus electron beams. The nature of that process produces corrosive gases that add significant wear and tear on the photocathodes, interrupting research for service and adding time and cost to projects.

«Accelerators of the future demand increasingly high-performance electron beams,» said Yamaguchi. «But those performance requirements dramatically outstrip the capabilities of present state-of-the-art electron sources.»

For photocathodes to work in next-generation accelerators, a suitable protective coating needed to be found. That’s because the reaction from photons striking the photocathodes to emit electrons also produces corrosive gas that can quickly degrade the bialkali thin-film photocathodes, made of antimony, potassium and cesium.

Story Source: Materials provided by DOE/Los Alamos National Laboratory. Note: Content may be edited for style and length.