Investigation of fast ion behavior using orbit following Monte–Carlo code in magnetic perturbed field in KSTAR
Investigation of fast ion behavior using orbit following Monte–Carlo code in magnetic perturbed field in KSTAR
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DOI：
10.1088/0029-5515/56/11/112018
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发表时间：
2016-08
期刊：
影响因子：
3.3
通讯作者：
K. Shinohara;Yasuhiro Suzuki;Junghee Kim;Jun Young Kim;Y. Jeon;A. Bierwage;T. Rhee
中科院分区：
文献类型：
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作者：
K. Shinohara;Yasuhiro Suzuki;Junghee Kim;Jun Young Kim;Y. Jeon;A. Bierwage;T. Rhee
采用轨道跟踪蒙特-卡罗（OFMC）程序，研究了KSTAR托卡马克装置在几种磁场配置和实际壁面几何条件下的快离子动力学和对等离子体部件的热负荷。特别是，注意到共振磁扰动（RMP）领域的影响。真空场近似以及自洽场，其中包括一个稳定的等离子体的响应被认为是。在这两种情况下，磁扰动（MP）是占主导地位的环形模式数n = 1，但其结构是强烈的等离子体响应的影响。当施加MP场时，快离子的损失显著增加。大部分损耗粒子在低场一侧的外中平面附近撞击极向限制器结构，但三个限制器上的热负荷分布随MP的形式而变化。也观察到了短时间尺度的损失，理应受到限制的共同通过快速离子。这些损失开始在几个极向过境后，快速离子出生后，在等离子体的高场一侧的磁轴深处。在所研究的配置中，这些损失是由两个因素的组合促进的：（i）由于低等离子体电流，快速离子在宽范围的磁性表面上的大的磁漂移，以及（ii）由外部RMP场在等离子体内部诱导的快速离子和磁性岛之间的共振相互作用。这些效应预计将在当今的托卡马克中发挥重要作用。
The fast ion dynamics and the associated heat load on the plasma facing components in the KSTAR tokamak were investigated with the orbit following Monte-Carlo (OFMC) code in several magnetic field configurations and realistic wall geometry. In particular, attention was paid to the effect of resonant magnetic perturbation (RMP) fields. Both the vacuum field approximation as well as the self-consistent field that includes the response of a stationary plasma were considered. In both cases, the magnetic perturbation (MP) is dominated by the toroidal mode number n = 1, but otherwise its structure is strongly affected by the plasma response. The loss of fast ions increased significantly when the MP field was applied. Most loss particles hit the poloidal limiter structure around the outer mid-plane on the low field side, but the distribution of heat loads across the three limiters varied with the form of the MP. Short-timescale loss of supposedly well-confined co-passing fast ions was also observed. These losses started within a few poloidal transits after the fast ion was born deep inside the plasma on the high-field side of the magnetic axis. In the configuration studied, these losses are facilitated by the combination of two factors: (i) the large magnetic drift of fast ions across a wide range of magnetic surfaces due to a low plasma current, and (ii) resonant interactions between the fast ions and magnetic islands that were induced inside the plasma by the external RMP field. These effects are expected to play an important role in present-day tokamaks.