Wavelength World Record at FLASH: 6.5 Nanometers! - Design value for laser flashes reached

Plot and numbers for experts: the wavelength spectrum at 6.5 nm. Number of bunches: 2 – aperture: 3 mm – wavelength: 6.523 nm – bandwidth: 0.0266 nm (rms)

Two weeks after the maximum beam energy of 1 gigaelectronvolt was reached, the control room announced another milestone: “On the evening of October 4, we observed lasing at a wavelength of 7 nanometers (nm) at FLASH for the first time.” Only 24 hours later, the FLASH team achieved the facility’s design value of 6.5 nm. In FLASH, the electrons are accelerated to an energy of 986 megaelectronvolts in six superconducting modules. On their flight through the undulator, the electrons now demonstrated the desired behavior also at this high energy: the spontaneous radiation they emit amplified itself to form the desired free-electron laser radiation pulses (SASE-FEL).