在托卡马克和其它环形核聚变装置中,纵向环形磁场的环效应是严重的。 式中,B为纵向磁场强度,Ⅰ为纵场线圈电流强度,N为匝数,r为距中心轴距离,μ为导磁率。从(1)式可以看出,B与r成反比(见图1),越向中心轴接近,纵场越强。在这一磁场中,线圈所受洛仑兹力各处不等,是角度θ的函数,即 In tokamaks and other toroidal fusion devices, the ring effect of the longitudinal toroidal magnetic field is severe. Where, B is the longitudinal magnetic field strength, I is the longitudinal field coil current strength, N is the number of turns, r is the distance from the central axis, μ is the permeability. From (1) can be seen, B and r are inversely proportional (see Figure 1), the closer to the central axis, the stronger the longitudinal field. In this magnetic field, the Lorentz force suffered by the coil varies from place to place, which is a function of the angle θ