Core Diagnostics for WENDELSTEIN 7-X Steady-State Exploration Until 18 GJ

This contribution provides an overview of the core diagnostics as they are required for W7-X steady-state high-density operation with a divertor and profile control. The inferred profiles then address the stellarator optimization. A particular task is the characterization of fast ion slowing down and -losses, which in a classical stellarator reactor could result in unacceptable wall loads and ultimately are deleterious for the heating efficiency. The energy dissipated during operation, 10 MW · 1800 s impacts on the technical diagnostic realization via loads to in-vessel components, quasi steady-state operation requires adequate data acquisition and control systems.