Characterization of 30-cm-Long Superconducting Undulator Coils With the Magnetic Measurement System CASPER II

The performance of superconducting insertion devices (IDs) in an electron storage ring strongly depends on their magnetic field quality. Therefore, it is essential to characterize the local field distribution and field integrals of the superconducting coils before installation in the final ID cryostat. The synchrotron radiation facility ANKA of the Karlsruhe Institute of Technology and Babcock Noell GmbH are collaborating on an R&D program on superconducting undulators (SCUs), which foresees the design, manufacturing, and characterization of an SCU with a 20-mm-period length (SCU20). Following this program, a magnetic measurement setup for conduction-cooled superconducting coils up to 2-m length (CASPER II) was built and commissioned. The system allows for performing training to maximum coil currents, measurements of the local field quality, and the first and second field integrals as well. In this contribution, we describe the measurement setup and, shortly, the magnet design and focus on the tests and measurement results of a 30-cm-long SCU20 coil package to highlight the potentiality of the test facility.