Compact spectrometer for the analysis of high harmonics content of extreme-ultraviolet free-electron-laser radiation

摘要: We present the design and characterization of spectrometer to be used at FLASH facility (DESY, Hamburg) to characterize spectral properties free-electron-laser radiation in terms high harmonics content. The spectrometer is sensitive 2-40 nm region. optical consists two spherical gratings with variable groove spacing and a extreme-ultraviolet-enhanced CCD detector. instrument are presented.