Iterative Kappa magnet pole shape optimization for MA core annealing

金属磁性体コアの磁場中熱処理のためのKappa電磁石磁極形状の最適化

Schnase, A.; 原 圭吾*; 長谷川 豪志*; 野村 昌弘  ; 大森 千広*; 島田 太平 ; 田村 文彦   ; 戸田 信*; 山本 昌亘   ; 吉井 正人*

Schnase, A.; Hara, Keigo*; Hasegawa, Katsushi*; Nomura, Masahiro; Omori, Chihiro*; Shimada, Taihei; Tamura, Fumihiko; Toda, Makoto*; Yamamoto, Masanobu; Yoshii, Masahito*

The accelerator cavities of J-PARC synchrotrons RCS and MR are loaded with Finemet FT3M cores. The performance of such MA (Magnetic alloy) cores can be improved with an external B-field during annealing. Such small size cores are available as FT3L. As the maker has no suitable magnet to operate while annealing large cores, we reused a magnet in the J-PARC Hadron hall for the trial production of large size cores similar to FT3L. This magnet was returned to the experiment group. The next setup uses the so-called Kappa magnet for a mass production scenario. The pole distance of the Kappa magnet is matched to the oven used for annealing. The pole surfaces are extended to reduce the current that gives the required B-field where the MA core is located in the oven. We describe a procedure, where the 2D magnet pole geometry is defined in Excel. An Excel macro calls the static field solver. The simulation results are processed and read back. This allows geometry studies, while keeping simulation results of magnet current and field distribution along the MA core consistent, although the magnet yoke is non-linear and several iterations are needed to find the current for the required B-field.