Influence of collisions on parametric instabilities induced by lower hybrid waves in tokamak plasmas
Influence of collisions on parametric instabilities induced by lower hybrid waves in tokamak plasmas
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DOI：
10.1088/0029-5515/56/1/016003
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发表时间：
2015
期刊：
影响因子：
3.3
通讯作者：
C. Castaldo;A. Di Siena;R. Fedele;F. Napoli;L. Amicucci;R. Cesario;G. Schettini
中科院分区：
文献类型：
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作者：
C. Castaldo;A. Di Siena;R. Fedele;F. Napoli;L. Amicucci;R. Cesario;G. Schettini
低杂波功率外耦合到托卡马克等离子体在等离子体边缘引起的参数不稳定性，通过天线频谱的展宽，强烈影响功率沉积和电流驱动的核心。在低杂波电流驱动实验中，对托卡马克等离子体边缘参数不稳定性的模拟一直忽略碰撞的影响。在目前的工作中，一个特定的碰撞参数色散关系，有助于分析这些非线性现象附近的低混合天线口，推导出第一次，基于动力学模型。数值解表明，在这样的冷等离子体区域的碰撞防止参数不稳定性的发病。这一结果对于目前的低杂波电流驱动实验以及聚变反应堆方案都很重要。
Parametric instabilities induced at the plasma edge by lower hybrid wave power externally coupled to tokamak plasmas have, via broadening of the antenna spectrum, strong influence on the power deposition and current drive in the core. For modeling the parametric instabilities at the tokamak plasma edge in lower hybrid current drive experiments, the effect of the collisions has been neglected so far. In the present work, a specific collisional parametric dispersion relation, useful to analyze these nonlinear phenomena near the lower hybrid antenna mouth, is derived for the first time, based on a kinetic model. Numerical solutions show that in such cold plasma regions the collisions prevent the onset of the parametric instabilities. This result is important for present lower hybrid current drive experiments, as well as in fusion reactor scenarios.