Oscillating Limiter Concepts

An oscillating multiple limiter concept for tokamak fusion reactors has been conceived. The limiters consist of half-circle or short arc segments in the poloidal direction. They are oscillated locally in the scrape-off layer. Alternately, each limiter will be in contact with the plasma for 50 ms or less at an interval of 0.5 s. It is shown that the limiter can be subjected to a transient heat load as high as 10 kW/cm² during the exposure time and can be cooled by water or helium in 0.5 s during the off-time. Only a few centimetres of movement is needed. A simple driving mechanism is also proposed.