Construction and First Magnetic Field Test of a Superconducting Transversal Gradient Undulator for the Laser Wakefield Accelerator in Jena.

A superconducting transversal gradient undulator (TGU), tailored to the particular beam properties of the laser wakefield accelerator (LWFA) at the University of Jena, has been designed and constructed at KIT. This undulator in combination with a specialized beam transport line will be employed to produce undulator radiation with natural bandwidth despite the relatively large energy spread of the electrons (ΔE/E0 ∼ 10 %) produced by the LWFA. The fabrication of this undulator and first results of the magnetic field measurement are discussed in this paper.