Abstract The plasma recovery after vessel vent is studied in the EAST 2019 spring campaign. The removal of condensate water is important for the fully superconducting tokamak. The low-Z impurities are mostly removed after a baking cycle for 200 h and GDC for 111 h. About 49% of H2 and 40% of H2O molecules are removed in this phase. The clean ultra-high vacuum pressure is re-obtained to 3.0 × 10−6 Pa. In a follow-up process, about ∼550 shots with an accumulated plasma duration of 4100 s are carried out to further remove implanted impurities. In the initial discharge stage, the removal rates of H2 and H2O particles are 4.7 × 1021 molecules/(m2·h) and 3.1 × 1021 molecules/(m2·h), respectively, which are ∼4 times higher than that during D2/He-GDC and baking. About 31% of H2 and H2O impurities are removed due to the effect of initial plasma shots. And the repeatable plasma shots are achieved with the decrease of impurity level. The results provide reference for the arrangement of recovery plan after vacuum failure of EAST, ITER, CFETR and superconducting fusion devices.

中文翻译：

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EAST 托卡马克容器排气后真空条件和等离子体性能的恢复

摘要 在 EAST 2019 春季活动中研究了容器排气后的血浆回收。冷凝水的去除对于完全超导托卡马克非常重要。在 200 小时的烘烤循环和 111 小时的 GDC 循环后，大部分低 Z 杂质被去除。在这个阶段，大约 49% 的 H2 和 40% 的 H2O 分子被去除。清洁的超高真空压力重新获得 3.0 × 10-6 Pa。在后续过程中，进行约 550 次喷射，累积等离子体持续时间为 4100 s，以进一步去除注入的杂质。在初始放电阶段，H2 和 H2O 颗粒的去除率分别为 4.7 × 1021 分子/(m2·h)和 3.1 × 1021 分子/(m2·h)，比 D2/ He-GDC 和烘焙。由于初始等离子体喷射的影响，大约 31% 的 H2 和 H2O 杂质被去除。并且随着杂质水平的降低，实现了可重复的等离子发射。研究结果可为EAST、ITER、CFETR和超导聚变装置真空失效后恢复计划的安排提供参考。