The optical layout is based on a plane grating monochromator (SX-700 type) operating in collimated light. This design combines high energy resolution with high efficiency using a small number of optical elements. At the same time it gives the user the freedom to optimize the higher harmonic rejection or the energy resolution depending on the experiment. We use a commercial monochromator developed in collaboration between BESSY and JENOPTIK. To allow for switching of the photon helicity, the twin undulators can be used as separate sources with different helicities.
More details about the beamline optics can be found here.
More details about the beamline optics can be found here.
| Optics | Plane grating monochromator |
|---|---|
| Photon energy resolution (E/ΔE) | > 5'000 |
| Grating | 300, 600, and 1'200 lines/mm |
| Cooling | Internal or side water cooling |
| Spot size on sample | 30 µm x 100 µm (V x H) |
Figure 1: Optical scheme of the SIM beamline showing the optical elements and their locations.
Figure 2: Spectrum of the UE56/I undulator as measured with a photodiode after the refocus mirror.