The W7-X ECRH Plant: Recent Achievements

The 10 MW, 140 GHz, CW ECRH‐plant for W7‐X is in an advanced state of commissioning and the installation was used to investigate advanced applications for extended heating‐ and current drive scenarios. The operation of the TED gyrotrons was recently extended to a 2nd frequency of 103.6 GHz at reduced output power and first results are presented. An improved collector sweep system for the W7‐X gyrotrons with enhanced power capability and smooth power distribution was developed, results are reported.