Design of a 4.7-T Wavelength Shifter with Cryogenic Permanent Magnets at NSRRC
Yung-Teng Yu1*, Chao-Chin Wang1,2, Hui-Huang Chen1, Ching-Shiang Hwang1,2, Cheng-Hsiang Chang1
1Magnet Group, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
2Graduate Program in Science & Technology of Synchrotron Light Source, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Yung-Teng Yu,
A 4.77 T wavelength shifter is designed for extending the X-ray spectrum beyond 50 keV in the 3-GeV storage ring of TPS. The compact 400 mm-long wavelength shifter is designed by using the PrFeB-based cryogenic permanent magnets to generate a 4.77 T at a 5 mm magnet gap. The 0.1% field uniformity on the transverse 40 mm is calculated. A cryo-cooler system with cryogen-free is designed to cool the magnets and to maintain the temperature of the magnets at 77 K in a vacuum chamber. Numerical simulation shows that the cooling system can cool the magnet array from 300 K to 77 K. In this paper, we present the high-magnetic-field performance and the cooling system for the wavelength shifter.

Keywords: Wavelength shifter, Multipole magnet , High magnetic field, Permanent magnet, Cryogenic