基于二次电子发射的离子束剖面测量

摘要

介绍了利用二次电子发射测量束流强度分布的基本原理.针对能量为几十keV的低能离子束,制作了一个基于印刷线路板工艺的离子束剖面测量系统模型.模型采用宽度1.8 mm的金属条作为收集电极,相邻两条之间的间距为2 mm.利用电子回旋共振源对束流剖面测量系统进行了性能测试,考察了网栅电压对信号收集的影响以及系统的线性响应和成像特性.结果表明,探测器输出信号与束流强度之间具有较好的线性关系,系统能得到离子束的一维横向强度分布,位置分辨率2 mm.%The principle of an ion beam profiler based on SEE(secondary electron emission) is introduced.For ion beams with energy of several tens of keV,an ion beam profiler prototype with sensitive area of 16 mm× 16 mm is constructed.The prototype only consists of an HV plane made of a metal mesh and a signal plane made of a printed circuit board (PCB).By test with an ECR source,the system shows very good linearity between the output signal and the intensity of the ion beam,and can obtain a one dimensional beam profile with a position resolution of 2 mm.