EAST准雪花偏滤器位形优化控制研究

The theory and experiments in many tokamak devices all around the world, proved the heat load reduction with Snowflake diverted shape (SF). As for EAST, we could not operate with standard Snowflake diverted shape due to the limitation of the Poloidal Field (PF) system, but we built the so-called Quasi-snowflake diverted plasma (QSF) with similar flux expansion, the peak heat load reduction reached ~50%, and the steady-state high-confinement QSF discharge has been reached up to 22s. In the project, we will focus on the optimized QSF shape control, try to build robust response model between PF coils and plasma, obtain effective decoupling between the fast-vertical position control and slow plasma shape control, achieve flexible and robust QSF shape control for steady-state high-confinement plasma discharge. After that, we can carry out the systematically study of heat load reduction with different QSF shape parameters under various plasma condition, obtain optimized long-pulse plasma discharges, provide experiences for future fusion reactor design.

理论与世界各大装置上的实验均证实雪花偏滤器位形可以有效降低偏滤器靶板热负荷，EAST装置因为极向场线圈特性无法建立高等离子体电流下的雪花偏滤器位形，但已经实现有相当磁通展宽的准雪花偏滤器位形，可以降低峰值热负载达50%，并实现了在此位形下最长达22s的长脉冲稳态高约束等离子体放电。本项目旨在完善EAST准雪花偏滤器位形反馈控制，可靠地控制准雪花偏滤器位形参数。建立EAST准雪花偏滤器位形下主动线圈对等离子体的响应模型，实现快速垂直位移控制与慢速垂直位移控制的有效分离，实现位形参数的多变量输入输出控制，建立EAST准雪花偏滤器位形下稳态高约束等离子体放电控制平台。研究多种放电条件下的准雪花偏滤器位形参数对靶板热负载降低的影响，从而优化长脉冲高参数等离子体放电实验，为中国未来聚变堆的物理设计提供依据。

本项目针对EAST准雪花偏滤器位形开展优化反馈控制研究，可靠地控制准雪花位形参数。建立EAST准雪花偏滤器位形下主动线圈对等离子体的响应模型，实现快速垂直位移控制与慢速位形控制的有效分离，实现位形参数的多变量输入输出控制，建立EAST准雪花位形下稳态高约束等离子体放电控制平台。研究多种放电条件下的准雪花偏滤器位形参数对靶板热负载降低的影响，从而优化长脉冲高参数等离子体放电实验，为中国未来聚变堆的物理设计提供依据。