Undulator for use as x-ray source in table-top free-electron laser, has quadrupole lenses whose magnetic axis is arranged about preset distance to form undulator field that emits undulator radiation to charged particle beam

摘要

The undulator has an undulator module with an integral multiple of four quadrupole lenses (Q1), where a charged particle beam e.g. electron beam or x-ray radiation, is introduced into the undulator. A magnetic axis of the quadrupole lenses is arranged about a predetermined distance beyond an initial longitudinal axis of the beam to form an undulator field. The undulator field acts on the beam as a magnetic dipole field and emits undulator radiation to the beam. The predetermined distance is adjusted to a phase relationship between the beam and the undulator radiation.