The Advanced Photon Source is heading towards its upgrade with a goal of becoming the brightest light source at the photon energies above 25 keV. A novel technology of superconducting undulators will help realize this goal. Although superconducting wigglers are quite common insertion devices installed on many light sources, this is not yet the case of superconducting undulators. These devices require solving many scientific and technological challenges such as making precise superconducting coils and achieving low field integrals andlow phase errors. In return, this technology can potentially open a way to the higher photon fluxes at higher energies that are not reachable with conventional undulators.
Meanwhile the APS team has already built and tested a short prototype superconducting magnetic structure. It was experimentally demonstrated that the required magnetic performance could be achieved without any additional magnetic shimming, a technique that is routinely used for conventional undulators.