Numerical investigation of energetic electrons in RF-wave driven spherical Tokamak plasmas

• Applicant: Dr.-Ing. Benedikt Roidl
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Fluid Mechanics
• Term: from 2015 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 279197977

The concept of fusion is characterized by many attractive features compared to conventional major energy options such as fossil, nuclear, or renewable sources. In terms of safety, fuel reserves, minimal damage to the environment, and efficiency fusion could represent a major contributor to the world's energy supply in the future. However, very difficult scientific and engineering challenges that are associated with the fusion concept have to be tackled and the known issues are being solved by global fusion research programs. To realize a stable thermonuclear fusion reaction the complex procedures to heat up the plasma and to ramp up and maintain the plasma current play a fundamental role. The application of RF-waves using specific spectra constitutes a promising and efficient procedure to meet these needs. However, the significant influence of energetic electrons in low-density plasmas on the stability and efficiency of the ramp-up procedure in Tokamak configurations has not been investigated in detail. The goal of the research project is to investigate the role of energetic electrons during the induction-free ramp-up process via novel numerical methods and consequently to develop more efficient ramp-up procedures. To reach the goal a non-linear magneto-hydrodynamic solver which is coupled with a kinetic particle formulation (MEGA) is adapted to deal with energetic electrons and extended by a modelled distribution function of electrons by using experimental data and results of reference numerical simulations. The analysis of the results of a realistic spherical Tokamak configuration investigating the role of energetic electrons is attended with MEGA coupled with a full-wave solver.

• DFG Programme: Research Fellowships
• International Connection: Japan
• Host: Professor Dr. Yuichi Takase