径向非均匀场分析磁铁出入射界面机械边界的确定

MECHANICAL BOUNDARY DETERMINATION OF AN ANALYSING MAGNET WITH RADIAL NON-HOMOGENEOUS FIELD

文章介绍了采用锥形极面且具有园弧形入射磁场边界的径向非均匀场分析磁铁出入射界面机械边界的确定方法。用一系列二维磁场计算来近似边界面附近的三维场计算,求得磁场等效边界与磁铁机械边界之间的关系,据此计算出与要求的场分布对应的机械边界的形状,并用合适的圆形弧边界代替所求得的曲线边界,确定出机械边界的实际参数。对于计算中采用的近似方法可能导致的偏差及其对系统光学性能的影响进行了详细的分析,并选用有效的修正措施保证了系统的光学参数满足设计要求。

A method for determing the mechanical boundaries of a radial non-homo-geneous magnetic field analysing magnet is proposed, which has conical poles andcurved effective field entrance boundaries. The relationship between the mechan-ical and the effective magnetic field boundaries is obtained by using a series oftwo-diniensional magnetic field calculations to approximate the three-dimensionalcalculation of the field around the boundaries. On the basis of calculations, thereal mechanical boundary parameter of the magnet are determined, in which thecurved entrance boundary is replaced by a circular one. The probable deviationsand their effects on the optical parameter of the system are analysed in detailand an effective corrections means is proposed to make the parameter, especiallythe resolving power reaching the desired values.