Two crystal x-ray spectrometers for OMEGA experiments.

Two x-ray spectrometers have been built for x-ray spectroscopy of laser-produced plasmas on OMEGA at the Laboratory for Laser Energetics (LLE) by Commissariat à l'Energie Atomique et aux énergies alternatives (CEA). The accessible photon energy range is from 1.5 to 20 keV. The first spectrometer, called X-ray CEA Crystal Spectrometer with a Charge-Injection Device (XCCS-CID), records three spectra with three crystals coupled to a time integrated CID camera. The second one, called X-ray CEA Crystal Spectrometer (XCCS) with a framing camera, is time resolved and records four spectra with two crystals on the four frames of a framing camera. Cylindrical crystals are used in Johan geometry. Each spectrometer is positioned with a ten-inch manipulator inside the OMEGA target chamber. In each experiment, after choosing a spectral window, a specific configuration is designed and concave crystals are precisely positioned on a board with angled wedges and spacers. Slits on snouts enable 1D spatial resolution to distinguish spectra emitted from different parts of the target.