Abstract
The objective of Wendelstein 7-X is to demonstrate steady-state operation at β-values of up to
5%, at ion temperatures of several keV and plasma densities of up to 2×1020 m−3. The second
operational phase foresees a fully steady-state high heat flux (HHF) divertor. Preparations are
underway to cope with residual bootstrap currents, either by electron cyclotron current drive or
by HHF protection elements. The main steady-state heating system is an electron cyclotron
resonance heating facility. Various technical improvements of the gyrotrons have been
implemented recently. They enable a reliable operation at the 1MW power level. Some of the
technical issues preparing plasma diagnostics for steady-state operation are exemplified. This
includes the protection against non-absorbed microwave radiation.
