A blade-free DC septum magnet with low leakage field

Septum magnet is a critical component in storage ring injection and extraction systems. The key issue is minimizing the leakage field while keeping the septum blade as thin as possible. Compared with pulsed septum magnets, DC septum magnets offer the advantage of reducing perturbations to the stored beam, provided that the challenge of effectively suppressing the leakage magnetic field can be overcome. Traditional DC septum magnet is limited in reducing the leakage field to a sufficiently low level due to the thickness constraint of the septum blade. In this paper, we introduce an innovative DC septum magnet that eliminates the septum blade while employing counteracting core and compensation striplines to significantly reduce the leakage field. Our simulation results demonstrate that the proposed design achieves the leakage field below 1.2 Gs, with the ratio of the stray field integral value to the main field integral value achieving <5 10 −4 . Importantly, the uniformity of the good field region remains unaffected after optimization.