Speaker
Zhengping Luo
(Institute of Plasma Physics)
Description
The Parallel plasma equilibrium reconstruction code PEFIT [1], first developed for real-time plasma shape control of the EAST tokamak (and capable of one full equilibrium reconstruction in 300ms with a calculation grid size in 65x65) is being adapted for use on MAST. PEFIT is based upon the EFIT equilibrium code algorithm, but rewritten in C using the CUDATMTM architecture in order to take advantage of massively parallel Graphical Processing Unit (GPU) processors to significantly accelerate the computation. This brings within reach the possibility of “full” equilibrium reconstruction within the real-time plasma control loop. Successful control using PEFIT/ISOFLUX has already been established in dedicated experiments on EAST. In addition to the real-time version, PEFIT provides detailed inter-shot analysis with a rapid turn-around. A PEFIT MDSplus module can be used to access diagnostic data and store the calculated results, or, alternatively, PEFIT is now interfaced to IDAM in order to be compatible with the MAST infrastructure and data model. A new flexible code customization technique (based upon XML) for different devices has been implemented into the code, making the development of PEFIT for MAST and other tokamaks much easier. On MAST, the total-induced passive current significantly affects sensor data and can adversely affect the reconstruction of the plasma equilibrium if not properly accounted for. A new induced current module based upon the lumped parameter circuit equation has been developed to estimate the induced currents within PEFIT. Preliminary testing indicates that results from PEFIT and EFIT++ are consistent with each other, with a single time-slice PEFIT reconstruction time of around 2ms for grid size in 65x65. Work is ongoing to optimize the algorithm further in order to satisfy the requirements of real-time plasma shape control.
[1] X.N. Yue, et al, Plasma Phys. Control. Fusion 55, 085016, 2013
Co-authors
Bingjia Xiao
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China;School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui, China)
David Muir
(EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire, United Kingdom)
Ivan Lupelli
(EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire, United Kingdom)
Lynton Appel
(EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire, United Kingdom)
Qiping Yuan
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China)
Xiaofang Pei
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China)
Yao Huang
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China)
Zhengping Luo
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, China)
