Investigation of conventional and Super-X divertor configurations of MAST Upgrade using scrape-off layer plasma simulation
Investigation of conventional and Super-X divertor configurations of MAST Upgrade using scrape-off layer plasma simulation
复制标题
使用刮除层等离子体模拟研究 MAST Upgrade 的传统偏滤器配置和 Super-X 偏滤器配置
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发表时间：
2014
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通讯作者：
A. Morris
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作者：
E. Havlícková;W. Fundamenski;M. Wischmeier;G. Fishpool;A. Morris
MAST升级偏滤器配置与刮削层等离子体模拟（SOLPS）5.0的第一批研究之一。我们专注于了解与Super-X偏滤器（SXD）的新几何形状相关的主要前景。这包括讨论磁通量膨胀和体积功率损失对减少目标功率负载的影响，偏滤器几何形状对偏滤器闭合的影响，偏滤器中中性物质和辐射的分布，以及连接长度在扩大目标润湿区域中的作用。MAST间ELM H模等离子体典型条件的比较证实了Super-X拓扑结构的性能改善，从而导致相对于中性粒子的偏滤器闭合明显更好（来自靶的原子通量增加了6倍，但从偏滤器到上部SOL的原子通量减少了2倍），增加的辐射体积和增加的总功率损耗（2倍），以及通过偏滤器中的磁通量膨胀和更大的体积功率损耗（在附着的等离子体中为5-10倍）来减少目标功率负载。由于体积功率损失的更大重要性，SXD对目标功率负载的减少随着碰撞性（高密度或分离状态）而进一步增加。据发现，冷偏滤器等离子体导致更强的平行温度梯度的SOL驱动更多的平行热通量，这意味着垂直传输的有效性，在目标上传播的功率可以降低，这需要考虑在任何优化。
One of the first studies of MAST Upgrade divertor configurations with scrape-off layer plasma simulation (SOLPS) 5.0 are presented. We focus on understanding the main prospects associated with the novel geometry of the Super-X divertor (SXD). This includes a discussion of the effect of magnetic flux expansion and volumetric power losses on the reduction of target power loads, the effect of divertor geometry on the divertor closure and the distribution of neutral species and radiation in the divertor, and the role of the connection length in broadening the target wetted area. A comparison in conditions typical for MAST inter-ELM H-mode plasmas confirms the improved performance of the Super-X topology resulting in significantly better divertor closure with respect to neutrals (the atomic flux from the target increased by a factor of 6, but the atomic flux from the divertor to the upper SOL reduced by a factor of 2), increased radiation volume and increased total power loss (a factor of 2) and a reduction of target power loads through both magnetic flux expansion and larger volumetric power loss in the divertor (a factor of 5–10 in attached plasmas). The reduction of the target power load by SXD further increases with collisionality (high density or detached regimes) thanks to the larger importance of volumetric power losses. It is found that a cold divertor plasma leads to stronger parallel temperature gradients in the SOL which drive more parallel heat flux, meaning that the effectiveness of perpendicular transport in spreading the power at the target can be reduced, and this needs to be taken into account in any optimization.