Numerical analysis of heat load distribution in Heliotron J with magnetic field tracing and plasma transport modeling
Numerical analysis of heat load distribution in Heliotron J with magnetic field tracing and plasma transport modeling
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DOI：
10.1088/1361-6587/ac2069
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发表时间：
2021-11-01
影响因子：
2.2
通讯作者：
Nagasaki, K.
中科院分区：
文献类型：
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作者：
Matoike, R.;Kawamura, G.;Nagasaki, K.
我们基于外围传输代码 EMC3-EIRENE，采用具有不同环形镜比率（凹凸度）的三种典型磁配置，对先进螺旋装置 Heliotron J 中真空室壁上的热负载模式进行建模和表征。使用 EMC3-EIRENE 代码评估的真空室壁上的热通量分布显示了几组热通量足迹，其中一些在使用磁场追踪代码获得的连接长度分布中看不到。这清楚地表明了在三维设备设计中除了磁场线追踪之外还需要等离子体建模。在高电子密度下，可以观察到热通量分布在环形和极向方向上的位移和扩展。由于热通量膨胀，热通量的峰值在高电子密度下降低。此外，提出了一种使用热分布函数的方法来评估整个真空室中的全局功率分布。评估结果证实了高电子密度下峰值热通量的降低和等离子体润湿面积的增加。低凹凸配置的热通量分布扩展更大，其中峰值热值比高凹凸配置低15%以上。
We model and characterize the heat load patterns on the vacuum chamber wall in an advanced helical device, Heliotron J, based on the peripheral transport code EMC3-EIRENE, in three typical magnetic configurations with different toroidal mirror ratios (bumpiness). The heat flux distribution on the vacuum chamber wall evaluated with the EMC3-EIRENE code shows several groups of heat flux footprints, some of which are not seen in the connection length distribution obtained with the magnetic field tracing code. This clearly shows the necessity for plasma modeling in addition to magnetic field line tracing in the design of three-dimensional devices. At high electron density, a displacement and an expansion of the heat flux distribution in both the toroidal and poloidal directions are observed. As a result of the heat flux expansion, the peak value of the heat flux decreases at high electron density. Further, an approach that uses the heat distribution function is proposed to evaluate the global power distribution in the entire vacuum chamber. The evaluation results confirm a decrease in the peak heat flux and an increase in the plasma-wetted area at high electron density. The heat flux distribution expansion is larger for the low-bumpiness configuration, in which the peak heat value is by more than 15% lower than that for the high-bumpiness configuration.