An undulator is an insertion device from high-energy physics and usually part of a larger installation, a synchrotron storage ring. It is a periodic structure of dipole magnets. A static magnetic field is alternating along the length of the undulator with a wavelength formula_1. Electrons traversing the periodic magnet structure are forced to oscillate. So the electrons give off energy as electronmagnetic radiation. The radiation produced in an undulator is very intense and concentrated in narrow energy bands in the spectrum. The light beam is also collimated on the orbit plane of the electrons. This radiation is guided through beamlines for experiments in various scientific areas.