Design of a REBCO thin film superconducting undulator

Recent developments have shown that superconducting undulators, mainly NbTi- based, outperform the existing devices. However, cooling these undulators is a challenge. REBCO (RE = rare earth, barium copper oxide) coated conductors (CCs) have been found to be a promising alternative to these materials due to their larger temperature stability margin and high engineering current densities. Here, we have investigated the feasibility of building an undulator magnetic structure using REBCO coated conductors and conducted experiments to evaluate their performance. The undulator coil has been wound with no inter-layer insulation. The critical current measurements at 77K showed that the winding of the undulator does not noticeably deteriorate the performance of the tape. Transient behaviour of the undulator has also been investigated and found to be characterized by long magnetic field decay times that result from current sharing between the windings. Steady-state operation was found to be very suitable for most undulator applications.