First FEL seeding in the extreme ultraviolet range at FLASH
Researchers from the University of Hamburg and DESY for the first time have operated DESY´s free-electron laser FLASH in direct seeding mode. By overlapping short, extreme ultraviolet laser pulses with the ultra-relativistic electron bunches in their experimental setup called sFLASH, the team improved the pulse properties in intensity and length compared to unseeded FEL flashes. The method allows to create fully coherent electromagnetic ...
Topping-out for new FLASH experimental hall
The building shell of the FLASH II experimental hall is finished. On 25 September, DESY, building firms and architects celebrated the completion of the roof of the experimental hall with a traditional topping out ceremony. The hall construction started in January this year. It is part of the FLASH II project, in which the accelerator of the free-electron laser FLASH is equipped with a second lasing beamline to serve more users with the ...
Improved method for orientation determination in single-particle imaging FEL experiments
Single-particle coherent diffraction imaging is one of the promising new techniques for the investigation of biological samples to sub-nanometer resolution. It has become possible only recently due to the development of X-ray free-electron lasers (XFELs), which produce ultra-short (10–100 fs), coherent X-ray pulses with high intensity. More than 1012 photons are produced in a single FEL pulse. Very short and intense pulses are ...
Hanbury Brown–Twiss interferometry explores SASE radiation at FLASH
The recent advent of x-ray free-electron lasers (FELs) with their unprecedented peak brilliance and ultrashort pulse duration has a revolutionary impact on the development of the x-ray science and opened the route to a number of spectacular groundbreaking experiments including femtosecond nanocrystallography and single particle coherent imaging. However, the properties of FEL radiation are not yet fully understood, in ...
Multi-photon interaction at FLASH lets electrons interfere
The behavior of atoms in strong electromagnetic fields shows often surprisingly complex results. A recent measurement at FLASH carried out by DESY scientists in collaboration with the Max Born Institute and the European XFEL as well as scientists from the Lund University and Universities San Sebastian and Moscow presents such complex effects. The angularly resolved photoelectron measurements show strong modulations indicating ...
