Statistical Analysis of Crossed Undulator for Polarization Control in a SASE FEL

Jan, 2008
14 pages
Published in:
  • Phys.Rev.ST Accel.Beams 11 (2008) 030702
e-Print:
Report number:
  • SLAC-PUB-13061

Citations per year

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Abstract: (arXiv)
There is a growing interest in producing intense, coherent x-ray radiation with an adjustable and arbitrary polarization state. In this paper, we study the crossed undulator scheme (K.-J. Kim, Nucl. Instrum. Methods A {\bf 445}, 329 (2000)) for rapid polarization control in a self-amplified spontaneous emission (SASE) free electron laser (FEL). Because a SASE source is a temporally chaotic light, we perform a statistical analysis on the state of polarization using FEL theory and simulations. We show that by adding a small phase shifter and a short (about 1.3 times the FEL power gain length), 9090^\circ rotated planar undulator after the main SASE planar undulator, one can obtain circularly polarized light -- with over 80% polarization -- near the FEL saturation.
Note:
  • 14 pages, 4 figures
  • 41.60.Cr
  • free electron laser: X-ray
  • free electron laser: SASE
  • undulator
  • statistical analysis
  • electric field