GYROKINETIC PARTICLE SIMULATION OF TURBULENT TRANSPORT IN BURNING PLASMAS (GPS-TTBP)
The newly formed GPS-TTBP is a U.S. Department Of Energy (DOE) Office of Science research sponsored center which has been founded on the campus of the University of California at San Diego (UCSD). This research is supported by funds from the Office of Science Scientific Discovery through Advanced Computing (SciDAC) Program as a cooperative agreement between the U.S. DOE and UCSD under Award Number DE-FC02-08ER54959. The Principal Investigator is Professor Patrick H. Diamond of the University of California at San Diego and includes the involvement of several other institutions and national laboratories.
The goal of this project is to develop the Gyrokinetic Toroidal Code (GTC) Framework and apply it to problems related to the physics of turbulence and turbulent transport in tokamaks, especially ITER. The project involves physics studies, code development, noise effect mitigation, supporting computer science efforts, diagnostics and advanced visualizations, verification and validation. The principal scientific themes of this project are mesoscale dynamics and non-locality effects on transport, the physics of secondary structures such as zonal flows, and strongly coherent wave-particle interaction phenomena at magnetic precession resonances.
We place special emphasis on the implications of these themes for rho-star and current scalings and for the turbulent transport of momentum. We also explore applications to electron thermal transport, particle transport; ITB formation and cross-cuts such as edge-core coupling, interaction of energetic particles with turbulence and neoclassical tearing mode trigger dynamics. Code development will focus on major initiatives in the development of full-f formulations and the capacity to simulate flux-driven transport. Multi-species and electromagnetic modules will also be developed. A major thrust of this program is to tackle the problem of noise due to growing weights in delta-f simulations.
In addition to the full-f -formulation, we plan to address this by developing numerical collision models and by employing methods for coarse graining in phase space. Verification will be pursued by linear stability study comparisons with the FULL and HD7 codes and by benchmarking with the GKV, GYSELA and other gyrokinetic simulation codes. Validation of gyrokinetic models of ion and electron thermal transport will be pursed by systematic stressing comparisons with fluctuation and transport data from the DIII-D and NSTX tokamaks.
A synthetic Beam Emission Spectroscopy diagnostic will be used as part of the validation program. The physics and code development research programs will be supported by complementary efforts in computer sciences, high performance computing, data management, etc. Work in advanced visualization techniques will be pursued to extract maximal information from the 5D gyrokinetic simulation results.