Mixed-material DIVIMP–WallDYN modeling, now incorporating ExB drifts, is presented that simultaneously reproduces tungsten (W) erosion and deposition patterns observed during the DIII-D metal rings campaign, in which a toroidally symmetric set of W-coated tiles were installed in the carbon (C) DIII-D divertor. Since most reactor plasma facing component (PFC) designs call for mixed-material environments, including ITER’s W/Be environment, the divertor targets will quickly evolve into reconstituted surfaces of multiple elements. This work identifies controlling physics that affects material migration patterns in the divertor, which impact PFC lifetimes and impurity leakage from the divertor to the core. These simulations indicate that radial and poloidal ExB transport dominates over parallel force balance for high-Z impurities such as W in the divertor region of DIII-D. It is demonstrated that ExB drifts are required to reproduce the experimental observation of non-local W and C co-accumulation in a band ∼7–9cm outboard of the outer-strike-point (OSP) W source, for attached L-mode conditions in the unfavorable ion grad-B drift direction. In addition, W gross erosion is localized to the region outboard of the OSP, as the formation of C co-deposits suppresses W erosion at the strike point. Time-dependent simulations with scaled ExB impurity drifts (60% of the OEDGE-calculated drift velocity) and W re-erosion quantitatively reproduce these features, including depth-resolved W/C ratios, within a factor of 2 over ∼115s of accumulated plasma exposure. The location of co-deposition regions is shown to be well-represented by an analytic leakage model, driven largely by poloidal ExB drifts. Qualitative agreement is also found between campaign-integrated W deposition measurements and simulations for the favorable ion grad-B drift direction, the standard mode of operation for most tokamaks. These results imply that a long-term inward radial migration of material from the outer divertor through the private flux region may occur in future devices.

混合材料 DIVIMP–WallDYN 建模，现在包含 ExB 漂移，同时再现了在 DIII-D 金属环活动期间观察到的钨 (W) 侵蚀和沉积模式，其中安装了一组环形对称的 W 涂层瓷砖碳 (C) DIII-D 偏滤器。由于大多数反应堆面向等离子体组件 (PFC) 设计需要混合材料环境，包括 ITER 的 W/Be 环境，偏滤器目标将迅速演变为多种元素的重组表面。这项工作确定了影响偏滤器中材料迁移模式的控制物理，这会影响 PFC 寿命和从偏滤器到核心的杂质泄漏。这些模拟表明，径向和极向 ExB 传输在 DIII-D 偏滤器区域中的高 Z 杂质（例如 W）的平行力平衡中占主导地位。已经证明，对于附加的 L 模式条件，需要 ExB 漂移来重现外打击点 (OSP) W 源外侧约 7-9 厘米波段中非局部 W 和 C 共积累的实验观察在不利的离子梯度B漂移方向。此外，由于 C 共沉积物的形成抑制了撞击点处的 W 侵蚀，因此 W 总侵蚀局限于 OSP 外侧区域。具有缩放 ExB 杂质漂移（OEDGE 计算漂移速度的 60%）和 W 再侵蚀的时间相关模拟定量再现了这些特征，包括深度分辨的 W/C 比，在累积等离子体的 115 秒内以 2 倍的系数进行暴露。共沉积区域的位置显示由分析泄漏模型很好地表示，主要由极向 ExB 漂移驱动。在活动集成的 W 沉积测量和有利离子梯度B 的模拟之间也发现了定性的一致性漂移方向，大多数托卡马克的标准操作模式。这些结果意味着材料从外部偏滤器通过私有通量区域的长期向内径向迁移可能会在未来的设备中发生。