Plasma position control using microwave reflectometry at COMPASS

The real-time control of a plasma position by the Plasma Position Reflectometer (PPR) was successfully demonstrated on the COMPASS tokamak.

This unique experiment took place thanks to the collaboration between microwave groups from the Instituto de Plasmas and Fusão Nuclear, Lisbon, Portugal and the Institute of Plasma Physics of CAS.

The Plasma Position Reflectometry (PPR) is perspective towards the future fusion devices. Microwave reflectometer can withstand extreme radiative and thermal conditions better than traditional magnetic diagnostics. These experiments are the continuation of previous work on the ASDEX Upgrade tokamak, where the first plasma position reflectometry demonstrations were originally made.

Fig: At 1100 - 1200 ms, plasma shifted radially by 2 cm and back. The plasma position is controlled by a signal from PPR (green). Measurements from magnetic diagnostics (blue) show a good match of the actual and desired (black) position of the plasma center.

28 Oct 2019