Stellarator Dynamics and Transport

The division is responsible for the engineering of Wendelstein 7-X and for the scientific investigation of collective dynamical phenomena that affect the plasma of the optimized Wendelstein 7-X stellarator on long and short length and time scales develops. Accordingly, the division is organizationally divided into two groups: Dynamics and Engineering.


Dynamical phenomena in plasmas have a fundamental spatio-temporal character, which requires sophisticated, often even imaging plasma diagnostic instruments. The division develops and operates these instruments at the Wendelstein 7-X stellarator and performs the interpretation of the measured data using model-based and statistical analysis methods. Closely related are essential elements of plasma transport for the particles in the plasma and the plasma energy, which directly determines the target parameters.

The group is divided into four specialized groups:

The physical properties of plasma equilibrium and plasma instabilities on large length and time scales are studied. This includes the study of so-called Alfvén eigenmodes, electromagnetic waves that can be excited, for example, by fast ions.  

Transport, impurities and radiation
The object of investigation here is particle transport, especially the sources and transport of impurity particles, which are responsible for a considerable part of the plasma radiation and thus play a significant role in the energy balance of the plasma.

Plasma instabilities driven by pressure gradients on short length and time scales (microinstabilities) are studied. These instabilities evolve strongly nonlinearly and appear in their consequence as plasma turbulence. Plasma turbulence dominantly determines the transport of plasma particles and energy.

Diagnostic technology
This is where the technical expertise for plasma diagnostic systems is pooled and made available to the scientific groups in the field. The development of scientific instruments ranges from conception and design to manufacturing, testing and installation.

Engineering Technology

Wendelstein 7-X is a technically highly complex experimental facility. This group is responsible for the maintenance and extension of the machine and the associated supply systems. This ensures that the operational readiness, safety and technical level of Wendelstein 7-X are maintained at the required high standard.

The group is currently divided into five specialized groups:

Torus Hall
This specialist group carries out the technical work on the actual Wendelstein 7-X facility. This includes extension work, modifications, necessary repairs and, on a pro rata basis, maintenance and testing work. During operation of Wendelstein 7-X, the specialist group supports the technical and operational processes.

Assembly technology
This is where the technological procedures, processes and instruments for the technical work at Wendelstein 7-X are developed. This includes planning and installation of the machine periphery as well as assembly planning and work preparation.

Engineering analysis
Ensuring the mechanical, thermal and electromagnetic integrity of Wendelstein 7-X under the various operating conditions requires complex and elaborate numerical calculations, which are performed in this specialist group. This also includes the maintenance of numerical models and the evaluation of sensor data during the operation of Wendelstein 7-X.

The division provides engineering development and design solutions, contributing to the operational objectives of Wendelstein 7-X. It also maintains and develops the design engineering infrastructure and models.

Supply systems
Continuous operation of a plasma requires extensive cooling of the components in the plasma vessel, for which this division is responsible. In addition, there are numerous other cooling circuits for heaters and plasma diagnostics. The second core task is to supply the heating systems of Wendelstein 7-X with high voltage in the megawatt range.


Go to Editor View