Speaker
Description
To produce nearly fully coherent hard X-ray self-seeded (HXRSS) free-electron laser (FEL) pulses, the forward Bragg-diffraction (FBD) monochromator is utilized at PAL-XFEL. These HXRSS FEL pulses exhibited exceptional peak-brightness and a narrow spectrum, demonstrating outstanding performance across a wide photon energy range from 3.5keV to 14.6keV. To further decrease the spectral bandwidth, a thinner diamond can be utilized. Using a diamond with a thickness of 30 μm, we experimentally obtained the bandwidth of ~160 meV (FWHM) at 11.21 keV for the self-seeded scheme. The spectrum was measured using a von Hamos spectrometer in RXES (resonant x-ray emission spectroscopy). In this talk, we will present recent experimental findings on the characteristics of the hard X-ray self-seeded FEL with different Bragg condition and thinner diamond crystal.
