补偿式螺线管的磁场

本文介绍一种由螺线管和一对圆形线圈构成的同轴、共心的组合线圈。当螺线管的直径和长度之比、一对圆形线圈的直径和间距之比、圆形线圈和螺线管韵直径比以及它们的匝数比或电流强度比取一定值时,非均匀磁场的三个主要项--二次项、四次项和六次项均可消去。计算结果（表1）表明,这种组合线圈的磁场均匀性较高,均匀磁场空间也相应地较大。

THE MAGNETIC FIELD IN A COMPENSATED SOLENOID

This paper introduces a coaxially and concentrically combined coil, constructed by a solenoid and a pair of circular coils. In this coil, when the ratio of diameter to length of the solenoid, the ratio of diam eter of the circular coils to the distance between them, the ratio of the diameter of the circular coils and the diameter of the solenoid, the turn ratio of the circular coils and the solenoid or the current intensityratio between them are of specific values, the three main terms-second, fourthand sixth order terms, of the non-homogeneous magnetic field, may vanish. The result of calculation （Table 1） shows that the magnetic field of the combined coil may be made more homogeneous and the extent of such homogeneous field is larger than that of the ordinary coil.