磁聚变等离子体中螺旋波加热和电流驱动集成计算的首个简化模型
First reduced model for integrated computations of helicon wave heating and current drive in magnetic fusion plasmas
AI总结：
该研究针对磁聚变等离子体中螺旋波加热和电流驱动计算成本高的问题，提出保留主要平行电子朗道阻尼通道的简化模型，经多装置样本测试及校正，能高效计算并给出有效性范围解释，偏差小且可再现电流密度分布。
AI中文摘要：
快速预测射频加热和电流驱动模型对托卡马克综合场景设计很重要，但螺旋波吸收的动力学计算对大规模参数扫描而言计算成本过高。我们提出了一种用于螺旋波加热和电流驱动的简化模型，该模型保留了主要的平行电子朗道阻尼通道。在冷等离子体色散根上评估波响应，并引入单朗道极校正以获得局部阻尼率和电流驱动效率的紧凑表达式。该模型以邱 - 陈加热模型为基准，使用约160万个涵盖EAST、HL - 3、DIII - D和KSTAR代表性条件的样本进行测试。发现简化误差主要由电子朗道参数和电子β决定。在确定的次低杂波频率有效性窗口内，不同装置的结果汇聚到一条共同的误差曲线上，这使得能够进行经验校正，并使用类似ITER和类似BEST的外推情况进一步测试。在接近和高于低杂波频率时，由于冷色散根结构的变化和单分支WKB描述的失效，一致性迅速恶化。当与简化的电流驱动源耦合时，校正后的加热模型与朗道通道Ehst - Karney参考值的中值偏差为10.8%，并再现了已发表的CFETR电流密度分布。所得模型为螺旋波加热和电流驱动计算提供了一种计算高效的简化封闭形式，以及对其有效性范围的物理解释限制。
英文摘要：
Fast predictive modelling of radio-frequency heating and current drive is important for integrated tokamak scenario design, yet kinetic calculations of helicon-wave absorption remain too computationally expensive for large-scale parameter scans. We present a reduced model for helicon-wave heating and current drive that retains the dominant parallel electron Landau-damping channel. The wave response is evaluated on the cold-plasma dispersion root, and a single-Landau-pole correction is introduced to obtain compact expressions for the local damping rate and current-drive efficiency. The model is benchmarked against the Chiu-Chan heating model using approximately 1.6 million samples covering representative conditions of EAST, HL-3, DIII-D and KSTAR. The reduction error is found to be governed primarily by the electron Landau parameter and electron beta. Within an identified sub-lower-hybrid-frequency validity window, results from different devices collapse onto a common error curve, which enables an empirical correction that is further tested using ITER-like and BEST-like extrapolation cases. Near and above the lower-hybrid frequency, the agreement deteriorates rapidly owing to changes in the cold-dispersion root structure and the breakdown of the single-branch WKB description. When coupled to a reduced current-drive source, the corrected heating model gives a median deviation of 10.8 percent from the Landau-channel Ehst-Karney reference and reproduces published CFETR current-density profiles. The resulting model provides a computationally efficient reduced closure for helicon-wave heating and current-drive calculations, together with physically interpretable limits on its range of validity.
