First lasing at a wavelength of 4.1 nm

The electron beam energy of SwissFEL was recently increased to above 900 MeV by successfully bringing two new accelerating modules into operation. This allowed SwissFEL to produce laser radiation for the first time in the soft x-ray regime with a photon wavelength of 4.1 nm. During the next months, the electron beam energy will be progressively further increased with the goal of enabling first user experiments at a wavelength of around 0.5 nm towards the end of this year.