Stellarator Wendelstein VII-AS: Physics and Engineering Design

The advanced stellarator Wendelstein VII-AS at the Max-Planck-Institut für Plasmaphysik, Garching, Federal Republic of Germany, is a medium-sized experimental machine with the following properties and aims:

1. a broadly optimized magnetic configuration with improved plasma equilibrium and smaller neoclassical transport losses compared to classical stellarators
2. operation with net-current-free plasma
3. field generation with a modular set of coils instead of the conventional helix/toroidal field coil system
4. good access for plasma heating methods, e.g., neutral beam injection, electron cyclotron heating, and ion cyclotron heating.

The physics characteristics and the engineering design of the experiment as well as results from the initial operation period are reported.