Source Characteristics

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.
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.