Radiation Pressure on Plasma Turbulence by Radio Frequency Waves

The use of radio frequency (RF) waves in fusion devices – primarily, to modify and control the heating and current profiles, and to subdue deleterious instabilities – has been gaining traction over the last few decades. The antennas or waveg- uide structures used for launching electromagnetic waves are usually located in the vicinity of the outer wall of a device. Consequently, for coupling RF power to core plasma, the waves have to propagate through a turbulent scrape-off layer plasma in the edge region. The RF waves can scatter off the turbulence, thereby altering the power profile coupled to the core. Simultaneously, the radiation pressure of the RF waves can affect the turbulence. Theoretically, it is convenient to analyze the two effects separately and explore the underlying physics. There have been a number of analytical and computational studies on the scattering of RF waves by different forms of plasma turbulence. This paper explores the impact of radiation pressure on turbulence.射频（radio frequency, RF）波在核聚变装置中的应用——主要用于调控加热与电流分布、抑制有害不稳定性——在过去数十年间愈发受到关注。用于发射电磁波的天线或波导结构，通常布置在装置外壁的邻近区域。因此，若要将射频功率耦合至核心等离子体，电磁波需穿过边缘区域内处于湍流状态的刮削层（scrape-off layer）等离子体。射频波会与湍流发生相互作用产生散射，进而改变耦合至核心等离子体的功率分布。与此同时，射频波的辐射压力也会对湍流演化产生影响。从理论研究的角度出发，将这两种效应分开分析以探究其内在物理机制，是较为便捷的研究范式。目前已有诸多针对不同类型等离子体湍流散射射频波的分析与数值计算研究。本文针对辐射压力对等离子体湍流的影响展开研究。