Development of NbTi planar superconducting undulators at the IHEP

Frontiers in Physics

Physics

Junhao Wei¹  Xiangchen Yang²  Xiaojuan Bian²  Yuhui Li²  Xiangzhen Zhang³  Zilin Chen³ 

[1] China Spallation Neutron Source, Institute of High Energy Physics, Chinese Academy of Sciences, Dongguan, Guangdong, China;Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China;Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China;School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China;

关键词: superconducting undulator;    NbTi;    free-electron laser;    vertical test;    phase error;   

DOI  :  10.3389/fphy.2023.1153005

 received in 2023-01-28, accepted in 2023-03-23,  发布年份 2023

来源: Frontiers

【 摘 要 】

Superconducting undulators (SCUs) have the advantages of generating stronger magnetic field and the radiation hardness compared to permanent magnet undulators. Therefore, SCUs are valuable to be applied in the free-electron lasers (FELs) driven by high-repetition-rate linear accelerators. The Insertion Device Group at the Institute of High Energy Physics (IHEP) in China started an R&D project to produce NbTi planar SCU prototypes with 15 mm period length. Several SCU prototypes, including short mock-ups, a 0.5-m-long SCU, and a 1.5-m-long SCU, have been successfully produced and cryogenic tested. The short mock-up coils were cooled by a liquid helium free cryostat to be quench trained at 4 K. The maximum current in the coils reached 500 A and the magnetic peak field exceed 1 T with 7 mm gap. The 0.5-m-long SCU was tested by using a vertical test system. The correction coils were confirmed with the ability in both correcting the magnetic field integrals and the phase error. The 1.5-m-long SCU was not only vertically tested, but also installed in a cryostat to be operated with high current over a long time. We applied the gap adjustment method to reduce the phase error within 9 degrees. The development of SCUs at the IHEP is introduced in this paper in detail.

【 授权许可】

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Copyright © 2023 Wei, Yang, Chen, Zhang, Bian and Li.