Nuclear Fusion ( IF 3.5 ) Pub Date : 2021-05-27 , DOI: 10.1088/1741-4326/abfb14 M. Gobbin 1 , L. Marrelli 1 , M. Valisa 1 , L. Li 2 , Y.Q. Liu 3 , G. Papp 4 , G. Pautasso 4 , P.J. McCarthy 5 , the ASDEX Upgrade Team , the EUROfusion MST1 Team
The data collected during ASDEX Upgrade experiments in which external 3D fields have been deployed in the attempt of mitigating runaway electrons (RE) are interpreted by a numerical test particle approach. To this end the Hamiltonian guiding center code ORBIT has been used, with the implementation of the magnetic perturbation spectrum modeled by the code MARS-F, which also takes into account the plasma response to the applied 3D fields. In agreement with the observed phenomenology, ORBIT simulations show that the configuration of the currents in the top/bottom arrays of error field coils, which maximizes the plasma response to the external perturbations, is the one that most affects the high energy test electron trajectories in the edge region, thus leading to an enhancement of the energetic electron losses. This occurs in particular during the disruption, i.e. taking into account the increased toroidal electric field associated with the fast plasma cooling. Used in a predictive way, the numerical results suggest which coil configuration could further improve the RE mitigation.
中文翻译:
3D 场在 ASDEX 升级中对失控电子缓解的作用:数值测试粒子方法
在 ASDEX 升级实验中收集的数据通过数值测试粒子方法来解释,其中已部署外部 3D 场以尝试减轻失控电子 (RE)。为此,使用了哈密顿引导中心代码 ORBIT,并实现了由代码 MARS-F 建模的磁扰谱,该代码还考虑了等离子体对应用 3D 场的响应。与观察到的现象一致,ORBIT 模拟表明,误差场线圈的顶部/底部阵列中的电流配置使等离子体对外部扰动的响应最大化,是对高能测试电子轨迹影响最大的配置。边缘区域,从而导致高能电子损失的增强。这尤其发生在破坏期间,即考虑到与快速等离子体冷却相关联的增加的环形电场。以预测方式使用,数值结果表明哪种线圈配置可以进一步改善 RE 缓解。