Bahrdt, J.; Follath, R.; Frentrup, W.; Gaupp, A.; Scheer, M.: Compensation of Beam Line Polarizing Effects at UE112 of BESSY II. In: Garrett, R... [Ed.] : SRI 2009 : the 10th International Conference on Synchrotron Radiation Instrumentation ; Melbourne, Australia, 27 September - 2 October 2009Melville, NY: American Inst. of Physics, 2010 (AIP conference proceedings ; 1234). - ISBN 978-0-7354-0782-4, p. 335-338
Abstract:
Reflections in synchrotron radiation beam lines tend to change the state of polarization of the radiation. This effect is more pronounced for steep angle of incidence, i.e. at low photon energy (say below 100 eV) beam lines. The APPLE II undulator UE112 at BESSY has all four magnetic rows shiftabel and thus generates any state of polarization. To provide any intended polarization state at the sample we perform polarisation measurements based on simple and fast linear polarization analysis that together with calculations of the undulator radiation predicts undulator settings that cancel beam line polarization effects.