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TONUS Research team

TOkamaks and NUmerical Simulations

Team presentation

The International Thermonuclear Experimental Reactor (ITER) is a large-scale scientific experiment that aims to demonstrate that it is possible to produce energy from fusion. It consists in confining a very hot hydrogen plasma inside a toroidal chamber, called a tokamak. In addition to physics and technology research, tokamak design also requires mathematical modeling and numerical simulations on supercomputers. The objective of the TONUS project is to deal with such mathematical and computing issues. We are mainly interested in kinetic and gyrokinetic simulations of collisionless plasmas. Together with other Inria teams, we also address related subjects: fluid plasma models; collisions; reduced, multiscale and asymptotic models; electromagnetism. We implement our methods in our two software projects: Selalib (Semi-Lagrangian Library) and CLAC (Conservation Laws Approximation on many Cores), adapted to new computer architectures. Finally, the TONUS project-team is at the interaction between mathematics, computer science, High Performance Computing, physics and practical applications.

Research themes

  • Mathematical modeling for plasma physics: in a tokamak, the plasma is collisionless and subject to a strong magnetic field. This requires the rigorous development of kinetic and gyrokinetic mathematical models based on asymptotic analysis.
  • Reduced modeling: the standard gyrokinetic model is a time-dependent Partial Differential Equation (PDE) set in a fifth-dimensional space. This leads to very expansive numerical simulations. We explore adaptive and reduced modeling technique for improving the algorithmic efficiency of the simulations.
  • Optimized plasma simulations: we develop two software libraries. Selalib is devoted to semi-lagrangian solvers for general kinetic equations. CLAC is a reduced Discontinuous Galerkin (DG) solver adapted to massively multicore computers architecture.

International and industrial relations

  • Max-Planck-Institut für Plasmaphysik (IPP), Garching, Germany
  • CEA Cadarache, Institut de Recherche sur la Fusion Magnétique (IRFM): development of the Selalib software library
  • AxesSim, Illkirch: development of commercial software for electromagnetic simulations.

Keywords: Plasma physics Gyrokinetic models Numerical simulations High Performance Computing