Hard X-ray Free Electron (XFEL) lasers produce extremely intense and ultra-short X-ray pulses, perfect for investigating the structure and dynamics of matter at atomic length and time scales. Operating for over a decade, these lasers have demonstrated a wide range of applications in physics, chemistry, materials science, and structural biology.
The European XFEL, one of the latest...
The FERMI free-electron laser (FEL) facility has recently reached an important milestone with the successful implementation of the echo-enabled harmonic generation (EEHG) scheme in the FEL-1 amplifier line. The maximum photon energy of FEL-1 has been doubled and the spectral quality of this FEL has been significantly improved. FERMI FEL-1 is now the first FEL operating in the 20-10 nm spectral...
Pulse duration of X-ray free-electron lasers (XFELs) is a key parameter for measurements with XFEL pulses. Recent efforts have enabled a direct diagnostics of pulse duration of XFEL pulses thorough an intensity autocorrelation (IAC) technique using two-photon absorption (TPA) [1] where two XFEL pulse replicas are mixed on a metal thin foil as the TPA medium, and then the nonlinear TPA signal...
X-ray vortices carrying tunable Orbital Angular Momentum (OAM) are an emerging tool for X-ray characterization technology. However, in contrast to the generation of vortex beams in the visible wavelength region, the generation of X-ray vortices in a controlled manner has proved challenging. Here, we demonstrate an X-ray free-electron laser oscillator (XFELO) can adjust only the kinetic energy...
Marcio Paduan Donadio, Marc Campell, Vincent Esposito, Philip Heimann, Dawood Alnajjar, Yuantao Ding, Thi Le, Alberto Lutman, Heinz-Dieter Nuhn, William Schlotter, Jan Gruenert, Kai Tiedtke, Fini Jastrow*, and Stefan Moeller
Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, 94025, United States
* European XFEL, Holzkoppel 4,...
Analog down-conversion structures have been used for beam diagnostics, especially in the processing of GHz frequency signals such as cavity BPM/BAM and bunch-by-bunch feedback. But the RF front-end module in the structure contains a large number of analog devices, which reduces the system performance, complicates the system, difficult to design and cost much. Digitizing the RF signal directly...
A new monochromator concept has been developed that allows tuning the bandwidth of the hard X-rays. The design is based on the 4f Fourier pulse shaping principles used in the table-top optical laser field. Very briefly, the X-ray beam is spatio-spectrally dispersed at the Fourier plane, where high-precision slits define the bandwidth that is encoded along the dispersive direction. The...
