Undulator radiation carrying spin and orbital angular momentum
Abstract
We show that the radiation from a helical undulator not only carries spin angular momentum (circular polarization) but also orbital angular momentum. This exotic property of the undulator radiation may be useful in coherent X-ray imaging and scattering experiments and to probe electronic transitions in matter by orbital dichroism spectroscopy. Also, we present that a new magnet configuration, similar to the structure of Figure-8 undulator or the PERA undulator, may generate right- and left-hand circularly polarized off-axis radiation simultaneously.
- Publication:
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Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- November 2007
- DOI:
- 10.1016/j.nima.2007.08.058
- Bibcode:
- 2007NIMPA.582...43S
- Keywords:
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- 41.50.+h;
- 41.60.-m;
- 07.85.Fv;
- X-ray beams and x-ray optics;
- Radiation by moving charges;
- X- and gamma-ray sources mirrors gratings and detectors