The source of the SIM beamline is a pair of permanent magnet helical undulators, which were built in collaboration with BESSY. It produces up to 1015 photons/second in a photon energy range of 95 - 2000 eV, which covers most relevant core levels from the Si-2p states (99eV) up to the rare earth d-states (~1500 - 2000eV).
More details about the beamline source characteristics can be found here.
    More details about the beamline source characteristics can be found here.
| Type | Elliptical twin undulator UE56 | 
|---|---|
| Period length | 56 mm | 
| Number of periods | 2 x 32 | 
| Gap | 18 - 150 mm | 
| Polarization | Linear: 0o (horizontal) to 90o (vertical) Circular: right / left | 
| K value | 4.4 - 2.2 | 
| Operating on harmonics | 1 - 7 | 
| Maximum field | 0.83 T / 0.66 T (H / V) | 
| Energy range | 95 - 2000 eV | 
Figure 1: The UE56 undulator prior to its installation in November 2001.
Figure 2: Calculated photon flux from the UE56 undulators of the SIM beamline.
 
 
