Photo Science and free electron lasers

While intense electron beams can directly be used for applications such as X-ray sources e.g. via betatron radiation from transverse oscillations inside the plasma wave, boosting them in brightness and energy via the plasma photocathode approach opens up completely new regimes of experiments. For example, electron beam brightness is the key parameter for photon sources: electron beam brightness begets photon pulse brightness. One focus area in our group therefore is exploitation of ultrabright electron beams to power hard X-ray free-electron lasers. In a collaborative R&D programme with Stanford, UCLA and ASTeC,, we have produced a forward-looking, high-fidelity start-to-end simulation framework that covers plasma acceleration and ultrahigh brightness beam production, beam transport and brightness preservation at the new nm-rad normalized emittance scale, and free-electron-lasing in advanced short-period undulators (see figure). This framework has been used to show that ultrahigh gain hard XFELs are possible, and that unprecedented attosecond-Angstrom level pulses may become viable. This is a vision we pursue in our lab. 

Attosecond-Angstrom free-electron-laser towards the cold beam limit, F.A. Habib et al., Nature Communications (2023)