Institute of Physics Publishing Plasma Physics and Controlled Fusion a Model of Elm Filament Energy Evolution Due to Parallel Losses
Institute of Physics Publishing Plasma Physics and Controlled Fusion a Model of Elm Filament Energy Evolution Due to Parallel Losses
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发表时间：
2005
影响因子：
3.1
通讯作者：
W. Fundamenski;R. A. Pitts;J. Efda
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文献类型：
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作者：
W. Fundamenski;R. A. Pitts;J. Efda
本文建立了两个简化的边缘局域模式（ELM）动力排气模型，一个基于动力学模型，另一个基于并行损失的流体处理模型。这些模型捕获了许多（尽管不是全部）动力学模拟的显著特征，大大节省了成本和复杂性（CPU时间以秒为单位，而不是以天为单位），使其成为实时解释工具或非线性MHD、传输和/或湍流代码模块的理想选择。动力学模型提供了沉积在分流器上的离子和电子功率的解析表达式，参数化为瞬态鞘层能量传输系数γ i和γ e，与粒子在电池中的模拟结果很好地吻合。该流体模型成功地再现了在JET上的外极向限制器测量的ELM灯丝密度和电子能量，以及最近在JET远刮层（SOL）中测量的ELM灯丝离子能量。从这个有利的比较中获得信心，然后使用相同的模型来预测由于i型ELM细丝在ITER限制器上的发生率而导致的离子冲击能量。虽然这些模型在这里只适用于elm，但它们有可能应用于其他托卡马克瞬态，如间歇性SOL爆发和中断热猝灭。
In this paper, two simplified models of edge localized mode (ELM) power exhaust are developed, one based on the kinetic and the other on the fluid treatment of parallel losses. These models are found to capture many (though not all) of the salient features of kinetic simulations at substantial savings in both cost and complexity (CPU time in seconds versus days), making them ideal as real time interpretive tools or as modules in non-linear MHD, transport and/or turbulence codes. The kinetic model offers analytic expressions for the ion and electron powers deposited on the divertor, parametrized in terms of transient sheath energy transmission coefficients γ i and γ e , in good agreement with particle-in-cell simulations. The fluid model successfully reproduces ELM filament densities and electron energies measured at the outer poloidal limiter on JET, as well as recent measurements of ELM filament ion energies in the JET far-scrape-off layer (SOL). Taking confidence from this favourable comparison, the same model is then used to predict ion impact energies due to the incidence of Type-I ELM filaments on the ITER limiter. Although the models are applied here exclusively to ELMs, they have a potential application to other tokamak transients, such as intermittent SOL bursts and the disruption thermal quench.