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

We present a $5\mathrm{m}$ 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 $400–1600\mathrm{eV}$ energy range. It is based on a variable line spacing spherical grating (average groove density of $3200{\mathrm{mm}}^{-1}$ , $R=58.55\mathrm{m}$ ) and a charge coupled device two dimensional detector. With an x-ray spot on the sample of $10\mu \mathrm{m}$ , the targeted resolving power is higher than 10 000 at all energies below $1100\mathrm{eV}$ and better than 7000 at $1500\mathrm{eV}$ . The off-line tests made with Al and $\mathrm{Mg}K{\alpha }_{1,2}$ fluorescence emissions indicate that the spectrometer can actually work at 12 000 and 17 000 resolving power at the $L_3$ edges of Cu $\left(930\mathrm{eV}\right)$ and of Ti $\left(470\mathrm{eV}\right)$ , respectively. SAXES (superadvanced x-ray emission spectrometer) is mounted on a rotating platform allowing to vary the scattering angle from 25° to 130°. The spectrometer will be operational at the ADRESS (advanced resonant spectroscopies) beamline of the Swiss Light Source from 2007.