EAST锂化系统的优化及其对等离子体性能的影响

Impact of Novel Lithium Coating Apparatus on Plasma Behavior Improvement in Experimental Advanced Superconducting Tokamak

为提高锂膜在先进实验超导托卡马克(EAST)内真空室器壁上的均匀性,从而提高锂膜对再循环的控制,对杂质的抑制能力,优化设计了新型三孔蒸发型坩埚,并成功的用于锂化壁处理实验。实验表明,锂膜在内真空室器壁上更加均匀,坩埚附近没有出现明显的锂膜起皮现象,下石墨偏滤器得到有效的覆盖。锂膜均匀性的提高,有效的提升了初次锂化壁处理对控制再循环,抑制杂质的能力,同时也延长了锂膜的寿命。为了恢复内真空室第一壁上退化锂膜的性能,优化设计了一套新型炮间锂化系统。新型炮间锂化系统成功在等离子体放电间隙开展了锂化壁处理,挡板开启后,锂蒸气成功注入到内真空室中,有效地抑制了等离子体放电中的再循环水平、杂质含量及总辐射功率。

A novel type of deposition tool was developed to improve the uniformity and service lifetime of the Li-coatings, grown on the wails of vacuum chamber dedicated to Experimental Advanced Superconducting Tokamak （EAST） and serving to reduce recyclability and suppress impurity contamination of the plasma. The original work was design of the crucible with three vaporizing holes. The test results show that the new evaporator outperforms the conventional one not only because of better uniformity, stronger interfacial adhesion and longer service lifetime of the Li-coatings, but also because of a considerable reduction of the recyclability, impurity contamination and total radia- tion power of the plasma; and that the Li-film fully covered the lower graphite divertor＇ s surfaces. Besides, another newly-designed inter-shot evaporator is capable of injecting Li-vapor and growing new Li-layers at the interval of discharges to restore the pre-coated lithium films.