Researchers exceed established X-ray energy limits in laser physics

A collaboration between TU Wien and the University of California San Diego has demonstrated that X-ray generation can exceed the long-accepted energy cutoff predicted by standard laser physics models. By directing powerful ultraviolet lasers at helium atoms, researchers produced X-rays with substantially higher energies than conventional theory allows.

The breakthrough is attributed to a unique quantum interaction where two electrons interact to release their energy simultaneously. Previously, the established model predicted that X-ray production would become extremely weak beyond a specific energy boundary determined by the properties of the incoming laser.

This discovery, published in Nature Photonics, builds upon the field of attosecond physics. The research utilizes mechanisms where a laser drives a freed electron away from its parent atom and then accelerates it back toward the atom, causing it to emit light upon collision. In this instance, the interaction between two electrons allowed for the production of higher-frequency light than previously thought possible.