磁聚焦法测电子比荷实验中电场对电子束螺旋线起点的影响

Influence of electric field on starting point of whorl of electron beam when measuring e/m by magnetic focusing method

利用2种磁聚焦方法,测量了e/m误差与加速电压和聚焦电压的关系.结果表明2种方法中,e/m误差对加速电压和聚焦电压的依赖关系不同.误差的根源可能是由螺距的不确定性引起,而螺距的变化是由螺旋线起点的变化引起的.讨论了螺旋线起点对加速电压和聚焦电压的依赖关系.

The relationship between the measurement error of e/m and accelerating voltage or fo- cusing voltage was determined using two magnetic focusing methods. The results indicated that the relation was different in these two magnetic focusing methods. The reason might be that the e/m error was caused by the screw-pitch error, and the screw-pitch error was caused by the shift of the starting point of the whorl. The relation between the starting point of whorl and the accelerating voltage or focusing voltage in these two magnetic focusing methods was discussed.