Modelling of dynamics and transport of carbon dust particles in tokamaks
Modelling of dynamics and transport of carbon dust particles in tokamaks
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DOI：
10.1088/0741-3335/49/4/001
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发表时间：
2007-04-01
影响因子：
2.2
通讯作者：
Mendis, D. A.
中科院分区：
文献类型：
--
作者：
Smirnov, R. D.;Pigarov, A. Yu;Mendis, D. A.
利用尘埃传输程序DUSTT对托卡马克聚变装置中尘埃粒子的传输进行了计算机模拟研究。报道了用DUSTT程序模拟的最新进展。改进的边缘等离子体尘埃动力学模型考虑了几个附加效应，包括影响尘埃充电和加热的热离子和二次电子发射，尘埃颗粒尺寸对热辐射的影响，以及等离子体中杂质的存在。结果表明，热离子发射导致等离子体对尘埃的加热增强，从而促进了尘埃粒子的破坏。引入托卡马克等离子体的区域结构，对尘埃生存条件进行定性分析。结果表明，在相对较冷的碳污染等离子体区域，尘埃粒子可以发生净沉积。采用区等离子体描述方法，对DIII-D装置中样品尘埃粒子的运动轨迹进行了模拟和分析。托卡马克边缘等离子体中尘埃特征的空间分布是通过粒子轨迹的统计平均来获得的。结果表明，托卡马克中的尘埃输运可以显著增强碳杂质对堆芯等离子体的穿透。
The transport of dust particles in tokamak fusion devices is studied using computer simulations with the dust transport code, DUSTT. Recent developments in modelling with the DUSTT code are reported. The improved model of dust dynamics in edge plasmas takes into account several additional effects, including thermionic and secondary electron emission which affects dust charging and heating, dust grain size effect on thermal radiation, and the presence of impurities in the plasma. It is shown that thermionic emission leads to enhanced dust heating by the plasma that boosts destruction of dust particles. The zone structure of tokamak plasmas is introduced for a qualitative analysis of dust survivability conditions. It is shown that a dust particle can experience net deposition in relatively cold carbon-contaminated plasma regions. Trajectories of sample dust particles in the DIII-D tokamak are simulated and analysed using the zone plasma description. Statistical averaging over an ensemble of particle trajectories is used to obtain spatial distributions of dust characteristics in the edge plasma of tokamaks. It is shown that transport of dust in tokamaks can significantly enhance penetration of carbon impurities towards the core plasma.