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22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone

Predict-First Analysis and Experimental Validation of MHD Equilibrium, Stability, and Plasma Response to 3D Magnetic Perturbations

23 Oct 2018, 08:30
Mahatma Mandir Conference Centre

Mahatma Mandir Conference Centre

Gandhinagar (nearest Airport: Ahmedabad), India
Poster P1 Posters


Dr Brendan Lyons (General Atomics)


An integrated-modeling workflow has been developed to predict equilibria and response to 3D magnetic perturbations in tokamak experiments. Starting from an equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver, EPED model for pedestal stability, and NEO drift-kinetic-equation solver (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape and various scalar parameters (e.g., normalized beta, pedestal density, $q_{95}$) are changed. These equilibria are then analyzed using automated M3D-C1 to compute the MHD plasma response to 3D magnetic perturbations. The workflow was created in conjunction with a DIII-D experiment studying the effect of triangularity on plasma response, showing excellent agreement between the analysis of the workflow's equilibria and equilibria reconstructed from the experiment. Various versions of the workflow demonstrated that the details of the edge current profile were not important for these cases, while $q_{95}$ and the details of the global pressure profile had a significant impact on the results. A predict-first study was then carried out for a DIII-D experiment examining how plasma response varies between single- and double-null shapes. The predicted equilibria were used to guide experimental planning and the predicted response was found to agree well with the perturbed magnetic field measured on the high-field-side midplane. Applications of this workflow to KSTAR and EAST experiments will also be explored. This work forms the basis of predictive scenario development across current and future devices (e.g., ITER), allowing for higher-fidelity predictions of MHD stability and 3D plasma response. Work supported by the US DOE under DE-FG02-95ER54309 and DE-FC02-04ER54698, along with NFRI, South Korea.
Country or International Organization United States of America
Paper Number TH/P1-8

Primary author

Dr Brendan Lyons (General Atomics)


Dr Carlos Paz-Soldan (General Atomics) Dr David Weisberg (General Atomics) Ms E. A. Belli (General Atomics) Dr Gunyoung Park (National Fusion Research Institute) Dr Guoqiang Li (Institute of Plasma Physica, CAS) Dr Lang Lao (General Atomics) Dr Morgan Shafer (Oak Ridge National Laboratory) Nathaniel Ferraro (Princeton Plasma Physics Laboratory) Dr Orso Meneghini (General Atomics) Dr Philip B. Snyder (General Atomics) Dr Todd E. Evans (General Atomics) Dr wenfeng guo (Institute of Plasma Physics, Chinese Academy of Sciences)

Presentation Materials