Sm_2Co_（17） magnet blocks for the in-vacuum undulators （IVU20） at the SSRF
摘要
The design and development status of Sm2Co17 magnet blocks for two in-vacuum undulators (IVU20) at the SSRF with the same hybrid design has been described. By the technological improvement of some processes and comparison with the experimental Sm2Co17 magnet blocks for the IVU25A, magnetic properties such as the intrinsic coercive force Hci and the average magnetic moment M are increased, the bend point magnetic field Hk value and pass rate are significantly increased, and the magnetic field uniformity of the magnet blocks are significantly improved. The basic developmental method of high uniformity Sm2Co17 magnet blocks for IVU20 is presented. The magnetic field qualities of the magnet blocks, including the magnetic property, the magnetic moment distribution, the magnetization deviation angle and the magnetic field uniformity, basically satisfy the specifications of the two IVU20 in-vacuum undulators.