Analysis of 3D Magnetic Fields in Wiggler Magnets for Free-Electron Laser

To obtain the desired magnetic flux density distribution, the authors studied modifications of wiggler magnets for use in free electron lasers. The effects of magnet positions and the magnetization within magnets on the flux density distribution in two dimensions in the cavity between magnets were clarified. A three-dimensional finite element method was used to calculate distributions, and good qualitative agreement obtained with experiments using ferrite plastic magnets.