Advanced Photon Source

An Office of Science National User Facility

Development of Superconducting Undulators

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.
Based on experience gained in the previous R&D feasibility study, the APS now has a design of the first test superconducting undulator. This design accumulates experience of Russian collaborators from Budker Institute in building cryostats for superconducting wigglers with the APS experience of building precise superconducting magnetic structures. The conceptual design is now being converted into the detailed engineering design, and manufacturing of the undulator has started.

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.

Conceptual drawing of the Superconducting Undulator cryostat assembly.

Superconducting Undulator core after winding and before epoxy impregnation.