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The Magnets group is responsible for the design and the magnetic field measurement of the magnets and insertion

devices for the particle accelerators, synchrotron light sources and free electron laser facilities.

The SSRF is a third generation synchrotron light source and can produce extremely bright x-rays from dipole magnets and Insertion Devices (IDs). The SSRF storage ring comprises 40 dipoles, 200 quadrupoles, 140 sextupoles, 80        corrector magnets and 40 corrector coils; the booster consists of 48 dipoles, 56 quadrupoles, 48 sextupoles and 56 correctors.

Strict field quality is specified for the SSRF magnets, especially for the storage ring magnets.  For the dipoles and       quadrupoles of the storage ring, the systematic and random tolerances for the harmonic contents of the integral fields   in the good field regions are required to be in the order of 10-4 and the RMS dispersions of the integral fields from   magnet to magnet are specified to be less than 10-3. The booster operates at the energy of 3.5 GeV with a frequency of 2 Hz. The dipoles in the booster are curved with 1.9 m long and all magnets have symmetric closed yokes.

In the phase-I beamlines of the SSRF, five IDs including two wigglers, two in-vacuum undulators (IVUs) and one     elliptically polarized undulator (EPU ) were built and installed. All five IDs are designed by the SSRF staffs and the   magnetic measurement and shimming for the two IVUs and the EPU are implemented in the magnetic measurement    laboratory of the SSRF. The calculated maximum R.M.S. phase errors of the two IVUs from the measured magnetic fields are 3.1° and 2.2°, respectively. For the EPU, the R.M.S. phase errors of less than 4° are obtained from the     measured magnetic fields in the horizontal polarization mode as well as in the vertical polarization mode.

Now the Magnets group is developing many magnets and undulators for Shanghai Soft X-ray Free Electron Laser     test Facility (SXFEL) and Dalian Coherent Light Source (DCLS). Some advanced undulators has been designed and implemented at the SSRF, including the cryogenic permanent magnet undulator (CPMU) and the exotic                    APPLE-KNOT EPU which can reduce the on-axis radiation power and restraint the higher harmonics efficiently.


                                       The group is currently composed of 8 members.



Qiaogen Zhou


Jidong  Zhang 


Miao   Zhang


Yongzhou  He


Hongfei Wang


Jingmin Zhang


Wei  Zhang


Maofei Qian  



Booster magnets in one cell




                                 Storage ring dipole                     Storage ring quadrupole         Storage ring sextupole




Two canted in-vacuum undulators                                                                            The double EPU