Simulations for DIII‐D high confinement mode plasmas with the multifluid code UEDGE show a strong role of poloidal E × B drifts on divertor heat transport, challenging the paradigm of conduction‐limited scrape‐off layer (SOL) transport. While simulations with reduced drift magnitude are well aligned with the assumption that electron heat conduction dominates the SOL heat transport, simulations with drifts predict that the poloidal convective E × B heat transport dominates over electron heat conduction in both attached and detached conditions. As poloidal E × B flow propagates across magnetic field lines, poloidal transport with shallow magnetic pitch angles can reach values that are of the same order as would be provided by sonic flows parallel to the field lines. These flows can lead to strong convection‐dominated divertor heat transport, increasing the poloidal volume of radiative power front, consistent with previous measurements at DIII‐D. Due to these convective flows, the Lengyel integral approach, assuming zero convective fraction, is expected to provide a pessimistic estimate for the radiative capability of impurities in the divertor. For the DIII‐D simulations shown here, the Lengyel integral approach underestimates the radiated power by a factor of 6, indicating that, for reliable DIII‐D divertor power exhaust predictions, full two‐dimensional (2D) calculations, including drifts, would be necessary.

中文翻译：

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EIII B倍体漂移在DIII-D中偏滤器传热中的作用

使用多流体代码UEDGE对DIII-D高约束模式等离子体进行的仿真显示，极向E  ×  B漂移在偏滤器传热中发挥着重要作用，挑战了传导受限刮擦层（SOL）传输的范式。尽管漂移量减小的模拟与电子热传导主导SOL传热的假设很好地吻合，但漂移的模拟预测，在附连和分离条件下，极向对流E  ×  B传热在电子导热中均占主导地位。作为倍数E  ×  B流动沿磁力线传播，具有较浅磁俯仰角的极向传输可以达到与平行于磁力线的声波所提供的量级相同的值。这些流动可能导致强对流主导的偏滤器热传递，从而增加了辐射功率前沿的多倍体体积，这与之前在DIII-D的测量结果一致。由于这些对流，假设对流分数为零，Lengyel积分法有望为偏滤器中杂质的辐射能力提供悲观的估计。对于此处显示的DIII-D模拟，Lengyel积分方法将辐射功率低估了6倍，这表明，对于可靠的DIII-D偏滤器功率排气预测，要进行完整的二维（2D）计算，包括漂移，