@article{5649,
  author = {P. J. Eecen and A. V. Tulupov and T. J. Schep},
  title = {Investigation of Multifrequency Generation in the Fem},
  abstract = {The FOM Fusion FEM project involves the construction and operation of a 1-MW, 100 ms pulse, rapid tunable FEM in the 130-250 GHz range for fusion applications. The undulator of the FEM consists of two sections with different strengths and different lengths separated by a gap without undulator field. The design provides arbitrary focussing. Single frequency codes predict a much higher output power for the two-section undulator than for a one-section undulator. However, the different undulator strengths lead to different resonance conditions and therefore, in principle, multiple frequencies can be generated. This problem of multi-frequency generation due to the two-section undulator is under investigation. First results are presented in this paper. The longitudinal mode structure of the FEM is simulated in a multi-pass, multi-frequency code. In this code the electrons are described fully 3D, non-wiggler averaged and in the long pulse limit. AC longitudinal space-charge forces are included. The radiation field is considered to have the known transverse radial dependence of a HE11-mode, due to the rectangular corrugated waveguide of the FEM. A multi-pass calculation in the single-frequency limit is presented, where the field grows into saturation.},
  year = {1994},
  journal = {Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment},
  volume = {341},
  number = {1-3},
  pages = {309-312},
  month = {Mar 1},
  isbn = {0168-9002},
  doi = {10.1016/0168-9002(94)90371-9},
  language = {eng},
}