Full-Scale Conduction-Cooled Superconducting Undulator Coils—Training, Stability, and Thermal Behavior

For several years, the Institute for Beam Physics and Technology (IBPT) at the Karlsruhe Institute of Technology (KIT) has collaborated with its industrial partner Babcock Noell GmbH (BNG) on the development of superconducting undulators (SCUs) for the electron storage ring ANgströmquelle KArlsruhe (ANKA), the test facility and synchrotron radiation source run by the IBPT, as well as low-emittance synchrotron radiation sources. After the successful test of the first full scale, 1.5-m-long, superconducting undulator with 15-mm period length in the ANKA storage ring, the collaboration is at present primarily working on an SCU with 20-mm period length (SCU20), foreseen to be installed at ANKA. The 1.5-m-long undulator coils have been tested in a horizontal, conduction-cooled measurement setup developed at the IBPT. This paper describes the training, stability, and thermal behavior of the coils.