Short-period electron beam wiggler

摘要

A free-electron laser comprises a wiggler for a linear electron beam, which wiggler has two sets of magnetic pole pieces (26, 28) which are arranged with periodic separation along opposite sides of the beam. The pole pieces (28) of one set are shifted by a half-period along the beam with respect to the pole pieces (26) of the other set. A uniform magnetic field running in the longitudinal direction generates, between the pole pieces, fields with transverse components (36) which alternate between the pole pieces (26, 28) of the sets and have a very short periodicity and consequently high frequency of the wave radiation. <IMAGE>