Simulation studies of divertor detachment and critical power exhaust parameters for Japanese DEMO design
Simulation studies of divertor detachment and critical power exhaust parameters for Japanese DEMO design
复制标题
日本DEMO设计偏滤器脱离和临界功率排气参数的模拟研究
DOI：
10.1016/j.nme.2020.100864
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发表时间：
2021
影响因子：
2.6
通讯作者：
Joint Special Design Team for Fusion Demo
中科院分区：
文献类型：
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作者：
N. Asakura;K. Hoshino;Y. Homma;Y. Sakamoto;Joint Special Design Team for Fusion Demo
处理从受限等离子体中排出的大量热能是 ITER 和 DEMO 中最重要的问题之一。日本 (JA) DEMO 反应堆 (Rp/ap= 8.5/2.42 m) 提出了一种传统的偏滤器，其具有与 ITER 相似的封闭几何形状和 1.6 m 的较长腿。通过 SONIC 仿真演示了 Ar 杂质引种的辐射冷却场景和偏滤器性能，以评估 JA-DEMO 2014（Psep~283MW 的原始设计）和具有更高等离子体伸长率的 JA-DEMO（Psep~235MW 的修订设计）中的功率排放。在降低辐射损失分数的严酷条件下，即f*raddiv=(Pradsol+Praddiv)/Psep和扩散系数(χ和D)下，确定峰值qtarget≤10 MWm−2的偏滤器运行在2–3×1019m−3的低值。偏滤器的几何形状和参考关键参数（f*raddiv~ 0.8，χ= 1 m2/s 和D= 0.3 m2/s）目前与该范围内的动力排放概念一致，并且修改后的JA-DEMO设计具有更宽的范围和足够的偏滤器操作余量的优点。对于严格假设off*raddiv~ 0.7 或χandD 到半值，初步设计需要更高的neep 操作，以控制peakqtarget≤ 10 MWm−2，即减小操作窗口。应用这两个严格的假设，两种设计的偏滤器在低气压范围内操作都很困难。
Handling of a large thermal power exhausted from the confined plasma is one of the most important issues for ITER and DEMO. A conventional divertor, which has the closed geometry similar to that of ITER and longer leg of 1.6 m, was proposed for the Japanese (JA) DEMO reactor (Rp/ap= 8.5/2.42 m). A radiative cooling scenario of Ar impurity seeding and the divertor performance have been demonstrated by SONIC simulation, in order to evaluate the power exhaust in JA-DEMO 2014 (primary design withPsep~ 283 MW) and JA-DEMO with higher plasma elongation (a revised design withPsep~ 235 MW). The divertor operation with the peakqtarget≤ 10 MWm−2was determined in the lownesepof 2–3 × 1019m−3under the severe conditions of reducing radiation loss fraction, i.e.f*raddiv= (Pradsol+Praddiv)/Psep, and diffusion coefficients (χandD). The divertor geometry and reference key parameters (f*raddiv~ 0.8,χ= 1 m2/s andD= 0.3 m2/s) were so far consistent with the power exhaust concepts in theneseprange, and the revised JA-DEMO design has advantages of widerneseprange and enough margin for the divertor operation. For either severe assumption off*raddiv~ 0.7 orχandDto the half value, highernesepoperation was required for the primary design in order to control the peakqtarget≤ 10 MWm−2, i.e. the operation window was reduced. Applying the two severe assumptions, the divertor operation was difficult in the lowneseprange for the both designs.