Abstract A double focusing ion-optical system consisting of oue cylinder electricfield and two magnetic fields is proposed in order to get uniform massdistribution in a mass ratio 4:1.

• 摘要 本文介绍由一个园柱电场和两个均匀磁场组成的离子光学系统,它可以在质量比4:1范围内达到双聚焦。