Optimization design and measurement of septum magnet with low leakage field

As one of the key components of synchrotron injection and extraction system, the perturbation of the beam generated by the septum magnet in the non-deflection direction will directly affect the orbit matching of the injected and extracted beam. Reducing the leakage field during the development of the septum magnet is a crucial one. Based on the theory of electromagnetic field, the leakage field analysis of septum magnet was carried out by using the electromagnetic field analysis software-Opera. In order to reduce the leakage field, the variation of the leakage field with different shielding structures were analyzed, and the shielding structure was optimized by using the parametric scanning finite element numerical calculation optimization method. Eventually, a leakage field shielding structure with multilayer metal plate combination was proposed, which significantly reduced the leakage field of the septum magnet. Furthermorethe magnetic field and leakage field were measured by using the Hall probe, and the measurement results are in good agreement with the numerical simulation results.