八角形线圈的亥姆霍兹模式

教科书中讲释亥姆霍兹线圈均以环形圈为模版。但在实际应用中,当需求规模较大尤其是建立三维体系时,为了便于定位,便于加工及节省材料,常采用正方形线圈为模版。不过线圈绕制中由于四个直角的应力作用,很难把握正方形线圈绕组的紧密和原型恆定、对称,显然这又有悖电磁学的诸多概念。鉴此,本文提出了以正方形为框架切去四角的八角形线圈模式,相应推出了满足亥姆霍兹线圈的基本条件,并给出了轴向磁感应强度的求解方程和均匀性的实测数据。

Octagonal Magnetic Coils of Helmholtz Model

According to schoolbook,a Helmholtz model consists of two identical circular magnetic coils that are placed symmetrically one on each side of the experimental area along a common axis.However,square magnetic coils are actually used to be located and constructed easily and save materials when the model is big and a three-dimensional system is necessary.Unfortunately,it is difficult to insure the compactness,invariance and symmetry of the square coils because of the stress of four right-angles.As a result,octagonal magnetic coils are brought forward in this issue.It is based on the structure of square coils whose four right-angles are removed.It also accords with the basic Helmholtz model.It has deduced solving equations of axial magnetic induction intensity and measured data of homogeneity.