EAST装置上离子回旋新型长天线的设计与耦合研究

Ion Cyclotron Range of Frequency (ICRF) heating is one of the main auxiliary plasma heating systems used in EAST tokamak device. It would be upgraded above 10MW high power. However,there was often seriously arcing happened on transmission line somewhere during each icrf campangin in EAST, which should be limited the high power operation. The optimization design of icrf antenna is a critical solution for higher capabilities of systems.A new toroidal long high radiation stripling antenna is proposed.This type of antenna has a possibility of improving the present ICRF antenna, which can effectively reduce the maximum voltage in transmission line and therefore improvement of power handling capability. Due to the better coupling in comparison with traditional antenna, it is less sensitivity for matching onto ELMS.The long RSA antenna is designed optimization by using maxwell solution code of HFSS and CST.The coupling of this long RSA antenna is studied by using TOPICA code including a 3D antennas geometry and with an accurate 1D plasma model. The design of long RSA antenna would provide an method for high power operation on EAST and an important guidance for ITER ICRF antenna design.

离子回旋系统是EAST装置上非常重要的辅助加热系统之一，EAST上的ICRF源功率即将升级到10MW以上。然而，在多轮实验中发现由于传输线上的高驻波电压造成频繁的传输线打火严重限制了高功率运行，最大注入功率仅35%左右。如何降低传输线高电压驻波是EAST上ICRF高功率运行目前急待解决的首要问题，天线设计是问题的关键。本项目提出一种新型的高辐射ICRF天线，能够大幅度提高天线的耦合效率，从而有效地降低传输线上高电压驻波。而且该天线不敏感于等离子体阻抗参数的变化，可以降低大ELMY对ICRF发射机的影响，保证高约束模式的维持。本项目通过利用HFSS，CST对新天线进行仿真优化，结合可包含复杂天线模型及实际的等离子体参数的耦合程序TOPICA对天线的耦合深入分析与研究。开展此项研究将为EAST上ICRF高功率稳态运行提供有力的保障；同时也为ITER装置ICRF天线的设计与优化提供一条新途径。

离子回旋系统是EAST装置上重要的加热系统，目前EAST具有12MW的源功率，然而耦合效率仅为35%左右，其原因可能在于现有短天线阻抗较低，高功率运行期间传输线上高驻波电压导致打火时常发生。如何提高天线耦合减低传输线电压是EAST上离子回旋目前急待解决的首要问题。本项目提出了一种新型的高辐射ICRF天线，能提高天线耦合，有效降低传输线上高电压驻波。根据EAST装置的参数，设计了一4电流带高辐射长天线，利用HFSS对包含复杂天线结构的模型进行了电磁仿真，对天线的辐射性能和电磁特性进行了计算分析和物理评估。在天线物理设计基础上完成了天线的工程研制并成功地安装到EAST装置上进行了初步的物理实验。实验结果验证了该天线较好的耦合特性，与传统天线相比能有效降低传输线驻波电压，而且该天线不敏感于等离子体阻抗参数的变化，可以降低大ELMY对ICRF发射机的影响，保证高约束模式的维持。通过新天线的发展，有效解决了低耦合、传输线高电压驻波打火的问题，为提高天线耦合和系统功率容量提供一种新途径。