加速器-电镜联机的离子光路及其调整方案

Optics Calculation and Beam Line Design for Accelerator-TEM Interface

离子辐照引起的材料微结构变化是一个复杂的过程,用加速器-电镜联机装置可原位观察载能离子束辐照引起的材料微结构演变。武汉大学加速器-电镜联机装置由1台2×1.7 MV串列加速器、1台200 kV离子注入机和1台200 kV透射电镜组成,通过自行设计的传输系统实现联机。本文介绍联机装置的光路布局,给出了静电加速器离子动力学计算程序LEADS(linear and electrostatic accelerator dynamics simulation)优化计算的结果,提出了两种改进方案,并用LEADS对改造后的加速器-电镜联机中离子运动进行了计算。结果显示,调整现光路二单元四极透镜的同时,在200 kV注入机90°偏转磁铁至电镜之间增加1个二单元静电四极透镜,将提高该系统中离子束传输效率。

Accelerator-transmission electron microscopy （TEM） interface useful tool for the study of materials because of its in situ observation fun applicable to the complex evolution of microstructures during ion irradiatio accelerator-TEM interface system in China has been established at Wuhan facility ction th IS a at is first University, which consists of a Hitachi H800 TEM, a 200 kV ion implanter and a 2 × 1.7 MV tandem accelerator. The paper gives the layout of the equipment and ion optical calculation results which provide possible adjustment of the system to improve its performance. The calculation result suggests that transport efficiency of the ion beam can be enhanced by adding another duality electrostatic quadruple in company with adjusting the original magnetic quadrupoles.