论文标题
一个三步模型，用于优化立方体形状磁罩内的线圈间距
A Three-step Model for Optimizing Coil Spacings Inside Cuboid-shaped Magnetic Shields
论文作者
论文摘要
提出了一个三步模型，用于计算由磁性屏蔽房间（MSR）等立方体内部线圈产生的磁场。盾牌被建模为两个无限宽度的平行板和一个无限高度的管。我们提出了一种改进的镜像方法，该方法考虑了有限厚度的平行板的效果。引入了一个反应因子来描述垂直管的影响，该垂直管是从有限元方法（FEM）模拟获得的。通过应用改进的镜像方法，然后将结果乘以反应因子，可以在快速计算中确定屏蔽体积内的磁通量密度。用FEM和使用超导量子干扰装置的MSR内部的Helmholtz线圈的场进行验证，并通过FEM进行了三步模型。与重复性耗时的FEM计算相比，该模型允许快速优化屏蔽耦合线圈间距。例如，我们优化了连接到MSR壁上的两个平行正方形线圈之间的距离。侧面长度为2.75 〜m的线圈原型的测量显示，在中央5〜cm上的磁场变化在2.7〜 \ textmuT上的磁场变化。这获得了6〜ppm的相对场变化，比我们先前使用的Helmholtz Coil小于5.4的相对场变化。
A three-step model for calculating the magnetic field generated by coils inside cuboid-shaped shields like magnetically shielded rooms (MSRs) is presented. The shield is modelled as two parallel plates of infinite width and one tube of infinite height. We propose an improved mirror method which considers the effect of the parallel plates of finite thickness. A reaction factor is introduced to describe the influence of the vertical tube, which is obtained from finite element method (FEM) simulations. By applying the improved mirror method and then multiplying the result with the reaction factor, the magnetic flux density within the shielded volume can be determined in a fast computation. The three-step model is verified both with FEM and measurements of the field of a Helmholtz coil inside an MSR with a superconducting quantum interference device. The model allows a fast optimization of shield-coupled coil spacings compared to repetitive time-consuming FEM calculations. As an example, we optimize the distance between two parallel square coils attached to the MSR walls. Measurements of a coil prototype of 2.75~m in side length show a magnetic field change of 18~pT over the central 5~cm at the field strength of 2.7~\textmu T. This obtained relative field change of 6~ppm is a factor of 5.4 smaller than our previously used Helmholtz coil.
