Speaker
Jiaxian Li
(Center for Fusion Science)
Description
The advanced configurations (snowflake and tripod) have been designed with EFIT based on current poloidal field (PF) coils system of HL-2M to study the advanced divertor physics and support the high performance plasma operation. The characteristic parameters of the advanced configuration (the distance between two X-points, magnetic flux expansion and weak field area and so on), especially the position of the second X-point, are the key factor for the advanced divertor studies. So the active magnetic control (especially X-points control) of the advanced configuration is essential for the operation and the study on physical mechanism of the advanced divertor.
A control algorithm for the advanced divertor configuration has been developed. The relationship between the X-point position and the PF coils current has been created by this algorithm with the magnetic filed of four control points near the divertor area. These magnetic filed can obtained from the RTEFIT. In addition, the isoflux control and the influence of the plasma motion have been also considered in the control algorithm. With this algorithm, the characteristic parameters, especially the position of the X-points, can be accurately tuned by regulating the current in PF coils (especial in divertor coils), meanwhile remain the plasma main parameters. For example, the second X-point (the first X-point is located at the separatrix of main plasma) can fluctuate around target plate of divertor, and the distance between two X-points can vary from 25cm to more than 50cm. These results can be useful for deeper understanding of the advanced divertor operation, and providing the reference database for determining whether the advanced divertor as a geometrical solution to reduce heat loads on the divertor plates for ITER or fusion reactors based on tokamak.
Co-authors
Guoyao Zheng
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
Jiaxian Li
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
Jinghua Zhang
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
Rui Ma
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
Xianming Song
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
Yudong Pan
(Center for Fusion Science, Southwestern Institute of Physics(SWIP), No.3,3rd Section, South of 2nd Ring Road, Chengdu, Sichuan , China, China)
