EAST装置中TZM材料基底表面硅化镀膜特性研究

Characteristic Investigation of the Silicon-Coated Films on TZM in EAST

文章研究了EAST聚变装置中,在离子回旋(ICRF)和直流辉光(GD)两种放电辅助下氘化硅烷与氦的混合气体(10%SiD4+90%He)在第一壁钛锆钼合金(Titanium-zirconium-molybdenum,TZM)表面硅化镀膜的特性。实验结果表明,相同工作功率的ICRF辅助硅化,烘烤温度更高比烘烤温度低的样件表面沉积的硅膜均匀光滑。这可能是由于样件表面烘烤温度越高,越有利于表面物理吸附的杂质气体的释放,从而获得致密平整的硅膜。相同烘烤温度(60℃)的ICRF辅助硅化,工作功率由20 kW提升至40 kW,样件表面沉积的硅膜Si含量增加,且硅膜的膜层厚约1.5 nm。这是因为提高ICRF工作功率,有助于清除TZM样件表面的氧化物和其他化合物,可增加SiD4电离和沉积,显著提高Si/O和薄膜厚度。相同烘烤温度(160℃)下,GD辅助硅化比ICRF辅助硅化沉积的硅膜厚约3.0 nm。这可能是由于GD相比于ICRF工作气压更高,工作时间更连续均匀。以上研究为EAST中评估钼基壁材料表面硅化镀膜效果对等离子体性能的影响及其在未来和聚变装置中的应用提供了有力的数据支持及实验积累。

Siliconization using 10%SiD4+90%He assisted by ion cyclotron range of frequency discharge(ICRF)or glow discharge(GD)was performed to investigate the characteristics of silicon(Si)film on titaniumzirconium-molybdenum(TZM)wall in EAST.The experimental results indicated that the Si film coated with higher baking temperature was more compact and flat compared with that with lower baking temperature under the same working power.It was possibly due to the release of more physically adsorbed impurity gas from the surface with the high baking temperature.With the same baking temperature,the ICRF working power improved from 20 kW to 40 kW,the content of Si was increased,and the thickness of Si film was thicker about 1.5 nm.The higher working power was helpful in removing oxides and other impurities on the TZM sample,and also could increase the ionization and deposition of SiD4.In addition,due to the higher working pressure and continuous working time,Sicoated film assisted by GD was thicker about 3.0 nm,compared with that assisted by ICRF.The above studies provide strong data support and experimental accumulation for EAST to evaluate the influence of silicon-coated film on TZM wall surface on plasma performance and its application in future fusion devices.