Nonlinear Theory of a Quadrupole Free Electron Laser

IEEE J. Quantum Electron. QE-33, 1621 (1987)https://ireap.umd.edu/10.1109/JQE.1987.10735261987Journal ArticleComplex and Emergent Systems

The nonlinear motion of electrons in a quadrupole free-electron laser is analyzed. If the betatron frequency is close to the mismatch frequency, the three-dimensional nonlinear equations can be reduced to an integrable one-dimensional equation. To enhance the efficiency, a tapered wiggler is introduced and the electron orbits in a tapered quadrupole free-electron laser are analyzed. The conditions for the particles to remain trapped as the heat wave decelerates are found.