The role of the sheath in magnetized plasma turbulence and flows
Event details
| Date | 28.10.2013 |
| Hour | 10:30 › 11:30 |
| Speaker | Joaquim Loizu, CRPP-EPFL |
| Location |
PPB 017
|
| Category | Conferences - Seminars |
The plasma dynamics in the SOL is crucial in determining the performance of tokamak devices, and constitutes one of the greatest uncertainties in the success of the fusion program. In the last few years, the development of numerical codes based on reduced fluid models has provided a tool to study turbulence in open field line configurations. In particular, the GBS (Global Braginskii Solver) code has been developed at CRPP and is used to perform global, three-dimensional, full-n, flux-driven simulations of plasma turbulence in open field lines. Reaching predictive capabilities remains, however, an outstanding challenge that involves a proper treatment of the plasma-wall interactions at the end of the field lines, to well describe the particle and energy losses. This involves the study of plasma sheaths, namely the layers forming at the interface between plasmas and solid surfaces, where the drift and quasineutrality approximations break down. In this talk we present progress in the understanding of plasma sheaths and their coupling with the turbulence in the main plasma. For the first time, a complete set of analytical boundary conditions that supply the sheath physics to fluid codes is derived and implemented in the GBS code. Simulations of SOL turbulence are carried out to investigate the importance of the sheath in determining the equilibrium electric fields, intrinsic toroidal rotation, and SOL width, in different limited configurations. For each particular study, simple analytical models are developed to interpret the simulation results and reveal the fundamental mechanisms underlying the system dynamics.
Practical information
- Informed public
- Free
Organizer
- Prof. P. Ricci, CRPP
Contact
- Prof. P. Ricci, CRPP