Plasma stability made to measure

After just a year of modification work, the first experiments have proven successful. Eight magnetic control coils on the wall of the plasma vessel of the ASDEX Upgrade fusion device have now succeeded in reducing perturbing instabilities of the plasma, so-called ELMs, to the level required. If these outbursts of the edge plasma become too severe, they can cause major damage to the plasma vessel in devices of ITER's class. The results now achieved go a long way towards solving this important problem for ITER.