医用加速器装置的离子源进气系统控制

Design of Ion Source Gas Control Used in Heavy Ion Medical Machine

HIMM是国产自主研发的医用加速器装置,作为目前最大的医学放疗装置,整个加速器控制系统的稳定性和可靠性要比工业系统有更高的要求。离子源针阀是离子源产生束流的重要组件,气体流量的大小和混合比直接影响源体真空度、电离效率、离子源稳定性等。本文针对HIMM离子源进气系统设计了基于三菱伺服电机和菲尼克斯PLC的控制系统,从系统结构、硬件设计、软件设计、数据分析等方面进行了介绍。为保证系统稳定性,加入伺服驱动器与相关真空度的硬连锁和远程开关功能。经过实际测试,该系统运行稳定,定位精度可达0.1°,满足设计要求。

HIMM(Heavy Ion Medical Machine)is a self-designed and independently developed medical accelerator device in China,the stability and reliability of the whole accelerator control system is higher than that of the industrial system.Ion source gas valve is an important component of ion source to generate beam.The gas flow rate and mixing ratio directly affects the vacuum,ionization efficiency and stability of ion source.This paper introduces the gas control system based on Mitsubishi servo motor and Phoenix PLC for HIMM ion source system.The system structure,hardware composition,PLC program,interface program and data analysis are presented.In order to ensure the stability of the system,hard interlocking with vacuum values and remote switching functions are added to the motion control.The actual test shows that the system runs stably and the positioning accuracy can reach 0.1°,which meets the design requirements.