Design study of a very large aperture eddy current septum for J-PARC

An eddy current septum has been studied for the 50 GeV main ring injection in the JPARC. Due to the high beam intensity, very large aperture is required to accommodate the large size injected beam. A large aperture magnet leads to significant end field and considerable eddy current losses, which degrades magnet performance and creates thermal problems. This paper discusses the eddy current effects on the field distribution and studies the methods for the eddy current effects compensation.