ASDEX Upgrade

ASDEX Upgrade ( Axially symmetric divertor EXperiment ) is the largest German in operation experiment in preparation for running in fusion reactors, nuclear fusion. It is from the Tokamak type and is located at the Max Planck Institute for Plasma Physics in Garching near Munich. On March 21, 1991, the first plasma. Since then, over 30,000 trials were conducted. Examines the behavior of plasma of hydrogen, but still none of the mergers provided or required deuterium and tritium mixture. This raises issues of plasma physics to be clarified, which are for the ITER fusion experiment of meaning, which is currently being built with respect to the target in the future electricity generation in nuclear fusion power plants.

ASDEX Upgrade is the successor of ASDEX and compared to other tokamaks of medium size. A special feature of this experiment is the complete tungsten lining of the inner wall which comes in contact with the plasma. Tungsten has a very high melting point of about 3000 ° C so that it withstands high temperatures. With respect to carbon, another common wall material of tungsten is expected that it takes up less radioactive tritium in a subsequent fusion reactor. Wolfram was it previously avoided because wall material passes through inevitable sputtering in the plasma whose properties would greatly deteriorated at an excessively high concentration of tungsten particles. In ASDEX Upgrade has been shown that the tungsten concentration in the plasma can be kept low enough with divertors even with a pure tungsten wall.

The experiment has a total radius of 5 meters and a total weight of 800 tons. The plasma can be heated up to 27 megawatts. Available heat sources are in addition to the ohmic heating by the plasma stream (about 1 MW) a neutral particle (up to 20 MW ) and wave heating in the ion and the electron cyclotron resonance ( each with up to 6 MW).