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Oct 13 – 18, 2014
Hotel Park Inn Pribaltiyskaya
Europe/Moscow timezone

Integrated Modeling of Tokamak Experiments with OMFIT

Oct 16, 2014, 2:00 PM
4h 45m
Green 8-9 (Hotel Park Inn Pribaltiyskaya)

Green 8-9

Hotel Park Inn Pribaltiyskaya

Saint Petersburg, Russian Federation
Poster Poster 6

Speaker

Dr Orso Meneghini (Oak Ridge Associated Universities)

Description

One Modeling Framework for Integrated Tasks (OMFIT) is a comprehensive integrated modeling framework developed to facilitate the interpretation of today experiments, enable theory validation, and support the design of next step devices. OMFIT is unique in its underlying data structure and grassroots approach. After only two years since the beginning of the project, the framework is now routinely used for frontline scientific research, and has an expanding collection of supported physics codes and workflows, which is driven by a growing number of users. OMFIT streamlined and increased the scientific throughput of a series of DIII-D experimental data analyses that are tedious, time-consuming, hard to track and error-prone if done manually. These include kinetic plasma equilibrium reconstruction, core and edge stability surveys, and critical-gradient transport studies. The effects on kinetic equilibrium reconstructions of using an exact neoclassical bootstrap current calculation or the approximate Sauter formula were evaluated. Magnetic flutter and neoclassical toroidal viscosity were shown to well describe the effect of resonant magnetic perturbations (RMPs) on edge transport and rotation. A neural-network approach was developed to perform nonlinear multivariate regression of transport fluxes as a function of local dimensionless plasma parameters, and showed excellent quantitative agreement with the DIII-D measurements. The numerical efficiency of the method makes it an ideal candidate for real-time transport simulations. Concerning predictive transport simulations, OMFIT made possible the design of a workflow that can efficiently find the self-consistent equilibrium and transport solutions by taking advantage of the time-scale separation between transport and current evolution. We found that the feedback between the transport fluxes and plasma equilibrium strongly affects the resulting kinetic profiles and can significantly improve the agreement with the experiments. This technique was validated on DIII-D data used to design baseline and advanced tokamak operational scenarios for both DIII-D and FNSF. Future work in this area of research will focus on including the EPED model in the workflow so to take into account the interplay between edge stability and core transport. Work supported in part by US DOE under DE-FG02-95ER54698
Country or International Organisation USA
Paper Number TH/P6-11

Primary author

Dr Orso Meneghini (Oak Ridge Associated Universities)

Co-authors

Dr Alan Turnbull (General Atomics) Mr B.A. Grierson (Princeton Plasma Physics Laboratory) Dr Christopher Holland (University of California San Diego) Ms E. A. Belli (General Atomics) Dr Gary M. Staebler (General Atomics) Dr Gloria Falchetto (CEA) Dr Guoqiang Li (Institute of Plasma Physica, CAS) Dr Holger St John (General Atomics) Dr Jeff Candy (General Atomics) Dr Lang Lao (General Atomics) Dr Nathaniel M. Ferraro (General Atomics) Dr Oliver Izacard (University of California San Diego) Dr Philip B. Snyder (General Atomics) Dr Qilong Ren (Institute of Plasma Physics Chinese Academy) Dr Ron Prater (General Atomics) Dr Sterling Smith (General Atomics) Dr Tom Osborne (General Atomics) Dr Vincent S. Chan (General Atomics)

Presentation materials