长脉冲电子回旋加热天线发射镜面分离式小流道热移除技术研究

Electron cyclotron resonance heating (ECRH) is a necessary heating and current drive means for the long pulse superconducting tokamaks and the next step devices. Electron cyclotron wave power is injected into the plasma through a quasi optical launcher. In long pulse operation, an efficient actively cooling design for mirrors is essential for reliable operation of the launcher, effective removal of the thermal stress is an important research work for ECRH launcher. The EAST 140GHz ECRH launcher mirror is capable of long pulse operation with embedded cooling channels in the mirror body, however, the precedure of mirror replacement is quite complicated. In requirements of easier maintenance and minimized edge current of the mirrors, this project proposes to optimize the cooling scheme with alternative detachable heat sink, detailed optimization of the smaller heat sink structure and its performance will be carried out. More attentions will be paied to the flexible combination of the heat sink and the optical mirror surface, therefore, in situ replacement of the thin copper sheet mirror surface is envisioned, so as to enhance the reliability of the launcher and to reduce the cost of the maintenance work. The work will also contribute to improve the steerable performances of the mirrors, it will provide a technical basis for the high performance experimental study on EAST.

电子回旋共振加热（ECRH）是目前长脉冲超导托卡马克装置以及未来聚变实验装置必不可少的加热和电流驱动手段。电子回旋波功率通过准光学发射天线注入等离子体。长脉冲运行条件下，天线镜面的有效冷却是决定其能否正常运行的关键因素之一，镜面在复杂运行工况条件下热应力有效移除是长脉冲发射技术研究的重要内容。本项目针对目前EAST 140GHz ECRH一体式主动水冷天线镜面维护工作难度大、不利于降低边界感应电流等问题，拟采用分离式热移除方案，结合长脉冲兆瓦级天线运行需求，研究小流道高效热交换技术。设计可与反射镜面分离的热沉结构，以实现镜面的原位更换，从而提高长脉冲ECH天线可靠性和维护工作的经济性，同时有利于优化ECRH天线高功率发射性能和动态调节性能，为EAST更高参数ECRH实验研究的顺利开展提供技术基础。

本项目结合EAST 长脉冲ECRH系统兆瓦级天线运行需求和镜面维护工序复杂的现状，开展了天线金属镜分离式热移除技术研究。以单波束反射镜为例，结合热机械性能分析，设计了三种小流道热沉，通过流热耦合分析，系统地研究了不同冷却结构热沉热移除特性；对热沉分离式天线反射镜进行了复杂流道成型及焊接工艺预研，对薄壁镜面与热沉连接结构进行了设计；结合天线运行工况，研制了散热性能测试验证系统，开展实验测试验证了理论分析与仿真设计。该设计方法可为长脉冲ECRH系统天线发射镜面的优化设计提供技术支持。相关研究结果也可为CFETR等装置多波束汇聚天线镜子设计提供基础。基于实验测试结果，镜面与热沉连接界面的接触热阻对散热性能的影响有待进一步研究。