快波模式转换效率的理论分析和数值模拟

利用相位积分法, 在传统的布登模型基础上, 考虑了高场侧截止层的影响, 构建了三体模型, 求出了快波通过单一衰减层的传输系数、反射系数和模式转换系数. 在双离子情况下, 模拟的结果与Kazakov等人的结果相符合. 针对EAST实验, 将双离子模型推广至三离子模型, 分析了不同相位、少子浓度、频率和纵场强度对快波模式转换效率的影响, 为未来离子回旋加热实验提供参考.关键词：模式转换加热离子回旋波加热相位积分

Theoretical analysis and numerical calculation of mode conversion efficiency of fast wave

By considering the effect of high-field-side cutoff, the conventional Budden model has been extended to Triplet model. In this model, the reflection coefficient, transmission coefficient and mode conversion (MC) coefficient of the fast wave for a single evanescence region can be derived through using phase-integral method. Furthermore, numerical calculation of MC coefficient for double-ion species and three-ion species have been done. In the case of double ions, the result is consistent with Kazakov's work. In addition, as an example of three ions plasma, (H, ³He)D plasma in tokamak EAST, simulations of the dependence of the MC efficiency on the magnetic field, microwave frequency and minority concentration for different antenna phasings are carried out. The results show how to choose proper phasing to reach an optimum MC efficiency. This result may provide a reference to improve ICRF heating efficiency.