Magnetic Field Analysis and Measurement of Pulsed Septum Magnet

Traditional off -axis injection becomes inadequate in diffraction limited storage ring (DLSR) for its small dynamic aperture (DA). On -axis injection with thin septum could solve the problem. This paper focuses on the theoretical calculation, field simulation, and measurement of thin septum magnets. The scheme of eddycurrent type thin septum magnets (the thinnest portion is with the thickness of 0.9 mm) was adopted with laminated silicon steel sheets as the magnet core. The simulation of main field, stray field along the beam trajectory, the leakage field decayed over 1 millisecond time was carried out within Opera 2D/3D. Field measurement and analysis of thin septum magnets also has been conducted comprehensively. The results meet requirements, and the work laid a foundation for injection technology of an advanced light source.