Portable, tunable, high-luminosity spherical crystal spectrometer with an x-ray charge coupled device, for high-resolution x-ray spectromicroscopy of clusters heated by femtosecond laser pulses

A portable (200x100x100 mm(3)), high-luminosity, spherically bent crystal spectrometer was designed for measuring in a wide spectral range of 1.2-19.6 Angstrom very low emissivity x-ray spectra of different clusters heated by 35 fs laser radiation. This spectrometer is associated with a custom design x-ray charge coupled device that features a large sensitive area (24.6x24.6 mm(2)) and a small pixel size (24x24 mum(2)). This apparatus provides simultaneous high spectral (lambda/delta lambda similar to 1000-5000) and spatial (40-80 mum) resolution. A large (30x10 mm(2)) open aperture mica crystal with R=100 mm is used as the dispersive and focusing element. The large tuneability of the spectrometer makes it possible to record high-resolution spectra of H-like ions of oxygen (CO2 clusters) in a spectral range of 15-17 Angstrom, Ne-like like ions of Kr in a spectral range of 5-5.7 Angstrom, and He-like spectra of Ar in a spectral range of 3.0-3.4 and 3.7-4.4 Angstrom without any adjustment of the spectrometer setup. Thanks to the high luminosity (high collection efficiency) of the spectrometer, high quality spectra were obtained using only 15 mJ 2000 laser shots. (C) 2001 American Institute of Physics.