HELIAS 5-B magnet system structure and maintenance concept

In addition to the previously presented option to separate the whole torus for good access to the in-vessel components, a blanket maintenance concept based on exchange of 400 large blanket segments simultaneously through five vertical ports was devised. Even though this concept is still at an initial state it can be shown that also in a complex stellarator geometry it is possible to have robots running on rails inside the plasma vessel to transport heavy loads.