SAXES, a high resolution spectrometer for resonant x-ray emission in the 400-1600 eV energy range

We present a 5 m long spectrometer for soft x rays to be used at a synchrotron radiation beamline for resonant x-ray emission spectroscopy and resonant inelastic x-ray scattering in the 400-1600 eV energy range. It is based on a variable line spacing spherical grating (average groove density of 3200 mm(-1), R=58.55 m) and a charge coupled device two dimensional detector. With an x-ray spot on the sample of 10 mu m, the targeted resolving power is higher than 10 000 at all energies below 1100 eV and better than 7000 at 1500 eV. The off-line tests made with Al and Mg K alpha(1,2) fluorescence emissions indicate that the spectrometer can actually work at 12 000 and 17 000 resolving power at the L-3 edges of Cu (930 eV) and of Ti (470 eV), respectively. SAXES (superadvanced x-ray emission spectrometer) is mounted on a rotating platform allowing to vary the scattering angle from 25 degrees to 130 degrees. The spectrometer will be operational at the ADRESS (advanced resonant spectroscopies) beamline of the Swiss Light Source from 2007.