Nuclear fusion is the energy of the sun and stars. The temperature in the sun’s core is approx. 15 million degrees centigrade. In order to achieve nuclear fusion on earth, temperatures of up to 150 million degrees are necessary. There is no material that could withstand direct contact with such a hot plasma. In tokamaks (such as e.g. JET and ITER), the plasma is confined with strong magnetic fields and thus separated from the wall.
In order to avoid undesirable effects such as collapsing of the plasma due to heat loss or damage to the first wall by energetic particle bombardment, experiments are carried out in European medium-size tokamaks (e.g. JET/CCFE - UK, ASDEX Upgrade/IPP Garching - Germany, TCV/EPFL, Lausanne - Switzerland etc.). The data obtained from these experiments are used for targeted modeling and simulation of the plasma in ITER in order to be able to predict its properties as accurately as possible. The computer codes used are continuously optimized and adapted, making use of modern computers that can handle huge data quantities.