Quadrupole-magnetic-pump-field free electron laser

摘要

A free electron laser in which the electron beam 12 is sent through the field of a quadrupole magnet 16 which may be untapered or tapered. The beam 12 is sent through the magnet 16 spaced from the symmetry axis of the magnet's poles 22 but on the focusing plane 20 of the quadrupole magnet 16.