Variable short period electron beam wiggler for free electron lasers

摘要

The free electron laser wiggler has therein a device for generating a variable short period wiggler field. A Type II superconducting material is formed into a field modifying means having a channel therein through which a beam of free electrons travels. The field modifying means is held within a vacuum chamber further having a source of external magnetic fields therein and a cooling means therein. The magnetic field generated must fall within the upper and lower critical magnetic field of the Type II superconducting material. The magnetic field penetrates the superconducting material generating a mixed state of superconducting and normal regions. The amplitude and period of the wiggler field in this structure can be controlled by varying the temperature, applied magnetic field, and the impurity concentration in the superconducting material to affect the fluxoid lattice. The electron beam interacting with this wiggler field outputs short wavelength radiation.