High-Resolution Imaging Spectrograph for the Ultrasoft X-ray Range

An imaging (stigmatic) spectrograph consisting of a plane VLS grazing-incidence grating and a normal-incidence focusing broadband multilayer mirror (Mo/Be, 111–138 Å, Mo/Si, 125–250 Å) that determines the working spectral range has been designed and tested experimentally. Line emission spectra of multiply charged ions excited in the laser plasma have been obtained. The spectral and spatial resolutions of the instrument were limited by the pixel size (13 μm) of the detector in use and were ~ 10 3 and 26 μm, respectively. The stigmatism of the instrument makes it possible to use it for spectral diagnostics of plasmas with a high spatial resolution. The size of the instrument is about 1 m.