Divisions

Stellarator Theory

Head: Prof. Dr. Per Helander

It is the aim of stellarator theory to find three-dimensional toroidal magnetic field configurations for plasma confinement suitable for a fusion reactor, and to describe the plasma behavior in such configurations.

Sufficiently good plasma properties resulting from two complementary theoretical descriptions are regarded as necessary for a fusion reactor.
The first one is the magneto-hydrodynamic theory (MHD) describing three-dimensional equilibria and their stability (characterized by a high ratio of plasma pressure to magnetic pressure). The second is the kinetic description of ions and electrons, which should predict good collisional confinement of the thermal plasma and good collisionless confinement of alpha-particles.

Wendelstein 7-X is an essential step towards a stellarator fusion plant and has been optimized theoretically with respect to this properties.

The work of the Stellarator Theory Division is nowadays focused on

Extended treatment of equilibrium and stability

calculation of three-dimensional plasma equilibria
MHD stability of stellarator plasma equilibria
Influence of fast particles on the stability of stellarator plasmas
gyrokinetic simulations of fast particles confinement in stellarators

Collisional and turbulent transport

kinetic description of neoclassical transport
gyrokinetic turbulence modelling
gyrokinetic PIC simulations

Three-dimensional edge physics

divertor transport
development of Monte-Carlo methods for edge physics
development of a general 3D FV transport code

Heating, current-drive and scenario modelling for W7-X

kinetic theory
electron cyclotron current drive in the TRAVIS-Code
one-dimensional transport modelling
neutral-beam current drive

The aim is both to broaden the general knowledge base of theoretical stellarator and fusion physics, and to provide explicit modeling and planning of experiments in Wendelstein 7-X.

Deutsch

Flux surface of Wendelstein 7-X.