医用加速器偏转线圈铜导线结垢过程研究

Study on scaling process of copper wire in deflection coil of medical accelerator

目的:探究医用加速器偏转线圈铜导线结垢过程,分析偏转线圈铜导线堵塞的原因。方法:选用T2黄铜在高纯除盐水中进行腐蚀结垢试验,通过伏安极化、恒电位还原和电子扫描电镜分析T2黄铜垢层的产生过程、化学成分及微观形貌,通过试验研究CO2在水中溶解对T2黄铜垢层剥落的影响。结果:T2黄铜在高纯除盐水中发生氧化还原反应,先生成紫红色的、结构致密的Cu2O内垢层,后生成黑褐色的、结构疏松的CuO外垢层。空气中CO2在水中溶解会加速结构疏松的CuO外垢层溶解剥落。结论:铜导线的氧化是形成铜垢的根本原因,冷却水中CO2的侵蚀会加速铜垢的剥落,从而引发偏转线圈堵塞、过热。

Objective To explore the scaling process of copper wire in the deflection coil of the medical accelerator,and to analyze the blockage cause of deflection coil copper wire.Methods The corrosion test of T2 brass in pure water was carried out in the laboratory.The chemical composition,growth process and microscopic shape of T2 brass scale layer were analyzed by electrochemical voltammetry,potentiostatic reduction and scanning electron microscopy.The effect of CO2 dissolution on the flaking of the copper scale was studied.Results T2 brass reacted with the dissolved oxygen in water to form a purple-red Cu2O inner scale layer and a taupe CuO outer scale layer.The dissolution of CO2 in the air lead to the dissolution and spalling of the loose CuO layer.Conclusion The copper scale is mainly caused by the oxidation of the copper wire,and the erosion of CO2 in the cooling water accelerates the flaking of copper scale,which makes the deflection coilclog and overheat.