The investigation of fuel retention in fusion experiments is important in view of plasma density control as well as tritium inventory for future fusion reactors. We present a first gas balance of the stellarator Wendelstein 7-X with its inertially cooled graphite divertor. The gas balance is used to estimate the wall inventory and it is found that the wall plays an important and dynamic role, absorbing or releasing particles depending on the plasma conditions. Several different scenarios are presented and the effect of fueling and heating on the wall inventory is assessed. We find that the record duration plasma experiment of 100 s required previous shorter plasmas to be successfully conducted.
聚变实验中燃料滞留的研究对于等离子体密度控制以及未来聚变反应堆的氚库存具有重要意义。我们首次对仿星器Wendelstein 7-X及其惯性冷却石墨偏滤器进行了气体平衡分析。利用气体平衡估算壁面库存，发现壁面在吸收或释放粒子方面发挥着重要且动态的作用，具体取决于等离子体条件。我们展示了多种不同情景，并评估了加料和加热对壁面库存的影响。我们发现，创纪录的100秒长脉冲等离子体实验需要先前较短等离子体的成功运行作为前提。