Two-Dimensional Coil System Compensating X, Y, Z-Components of Leakage Field from an Aperture of Magnetic Shields and its Application to a Large-Scale Cylindrical Shield

补偿磁屏蔽孔径漏磁场X、Y、Z分量的二维线圈系统及其在大型圆柱形屏蔽中的应用

• 批准号: 04555094
• 负责人: SASADA Ichiro
• 金额: $ 2.82万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04555094/
• 关键词: Magnetic shield; Magnetic shaking; Figure-eight coil; Opening compensation; Cylindrical shield; Amorphous magnetic material; Biomagnetism; Magnetic field measurement

A new method was developed by which magnetic fields coming in through an opening of a magnetic shield can be compensated. The earth's magnetic field and ac magnetic field were targeted as external magnetic fields to be compensated by the method. A large-scale cylindrical shielding case was developed for this study using a Permalloy cylindrical case (outer diameter =68cm, length=180cm) with an opening at an end and Metglas 2705M amorphous ribbons, which were wound helically on the outer surface of the Permalloy case by 16 layrs. Magnetic shaking field was applied to only the amorphous layrs by a toroidal shaking coil of 36-turns. The cylindrical shielding case was laid on the floor with its axis perpendicular to the direction of the earth's magnetic field. The earth's magnetic field was attenuated to below 0.1 mG (10 nT) at the central region of the shield. The distribution of residual magnetic field was nearly flat due to the cylindrical shape. The horizontal component of the earth's field (0.32 G) as well as vertical one (0.35 G) was compensated at the open end of the cylindrical shield using a flat figure-eight coil (74 cm in diameter) controlled by a feedback system corresponding to each component. Effectively shielded area where residual magnetic field was less than 0.15 mG was extended by about 30 cm (approximately by a radius) toward the open end. Compensating current for the horizontal component of the earth's field was 2.3 A-turn. Magnetic field applied axially by a large square coil was also compensated using a ring coil of the same diameter.By incorporating a newly developed compensating technique we successfully constructed a prototype magnetic shield of human size which is light-weight, high-performance and low-cost

开发了一种新方法，可以补偿通过磁屏蔽开口进入的磁场。该方法将地球磁场和交流磁场作为外部磁场进行补偿。本研究开发了一种大型圆柱形屏蔽壳，采用端部开口的坡莫合金圆柱形壳（外径=68cm，长度=180cm）和Metglas 2705M非晶带，在坡莫合金壳的外表面上螺旋缠绕16层。通过36匝环形振荡线圈仅对非晶层施加振荡磁场。圆柱形屏蔽罩放置在地板上，其轴线垂直于地球磁场的方向。地球磁场在屏蔽中心区域衰减至 0.1 mG (10 nT) 以下。由于呈圆柱形，剩余磁场的分布几乎是平坦的。地球磁场的水平分量（0.32 G）和垂直分量（0.35 G）在圆柱形屏蔽的开口端使用扁平八字形线圈（直径 74 厘米）进行补偿，该线圈由与每个分量相对应的反馈系统控制。剩余磁场小于0.15mG的有效屏蔽区域向开口端延伸约30cm（大约半径）。地磁场水平分量的补偿电流为 2.3 A 匝。大方形线圈轴向施加的磁场也使用相同直径的环形线圈进行补偿。通过采用新开发的补偿技术，我们成功构建了一种轻质、高性能、低成本的人体尺寸原型磁屏蔽

项目成果

I.Sasada, I.Inoue, K.Harada: "Multipole Shaking field for Magnetic Shaking" IEEE Transactions on Magnetics. Vol.28, No.1. 3 (1992)

I.Sasada、I.Inoue、K.Harada：“磁振动的多极振动场”IEEE 磁学汇刊。

I.Sasada, Y.Ohnaka: "Experimental study on opening compensation for magnetic shield by current superposition" Journal of applied Physics. Vol.75, No.8, (in print). 3 (1994)

I.Sasada，Y.Onaka：“电流叠加磁屏蔽开路补偿的实验研究”应用物理学杂志。

笹田一郎: "実用規模磁気シェイキング付き磁気シールドの基礎特性" 電気学会マグネティックス研究会資料. MAG-93-62. 31-40 (1993)

Ichiro Sasada：“具有实际规模的磁振动的磁屏蔽的基本特性”日本电气工程师学会磁学研究组的材料 MAG-93-62（1993）。

笹田一郎: "大型円筒磁気シェイキング付き磁気シールドの基礎特性" 日本応用磁気学会誌. 18-2(印刷中). 4 (1994)

Ichiro Sasada：“大型圆柱形磁振动的磁屏蔽的基本特性”，日本应用磁学学会杂志 18-2（出版中）。

I.Sasada, Y.Ohnaka: "Fundamental Characteristics of a Large-Scale Cylindrical Magnetic Shield with Magnetic Shaking (in Japanese)" Journal of Magnetic Society of Japan. Vol.18, No.2, (in print). 4 (1994)

I.Sasada、Y.Onaka：“具有磁振动的大型圆柱形磁屏蔽的基本特性（日语）”日本磁学会杂志。