Electron dynamics and transverse-kick elimination in a high-field short-period helical microwave undulator

Single electron dynamics for a circular polarized standing wave (CPSW) undulator synthesized from a corrugated cavity operating with a very low-loss HE11 mode are analyzed. The mechanism of the transverse drift of the CPSW undulator and its elimination are researched, and the tapered-field ends are found effectively to suppress the kick. A prototype of the CPSW undulator with the characters of short undulating-period 1.4 cm, high field K ∼ 1, large aperture ∼ 5 cm, and variable polarization is designed and modeled, whose 3-dimensional electromagnetic fields are used to research the suppression of the transverse kick.