Design Study for HybriSCU: A HYBRID NbTi/ReBCO Superconducting Undulator

At the European XFEL, the undulator systems group has started in 2020 an R&D project dedicated to the development of innovative superconducting undulator (SCU) coils. SCUs are of great interest for storage rings and free electron lasers (FEL) facilities as they enable to widen the tunability range of the generated photon energy for the same electron beam energy compared with the established technology of the permanent magnet undulators. In this contribution, we present the characterization study and the achievable performance of HybriSCU a graded SCU coil combining two different superconductors: NbTi and high temperature superconductor (HTS) based on Rare-Earth Barium Copper Oxide (ReBCO) tape.