Tokamak Scenario Development
The Tokamak Scenario Development Division (E 1) operates the tokamak ASDEX Upgrade which concentrates on treating the physical principles for a fusion power plant. Prominent is the preparation of the ITER large-scale experiment and the european demonstration power plant DEMO.
On the one hand, points critical to the designing of the technical systems of ITER are being investigated; on the other, the operation of ITER and DEMO is being prepared by developing suitable plasma states, so called 'scenarios'. Improvement of the standard operation scenario to enhance stability, confinement quality, and pulse length is also a major concern. Such plasma states should make it possible to achieve a much higher fusion power and longer pulse length in ITER. For such discharges with good confinement at high heating power it is also being attempted to optimise energy transport and particle control – including exhaust of the helium ash – and develop methods of controlling ELMs (edge-localised modes). All these points are also of high importance for the operation scenario of DEMO; in addition, it will be investigated in which points the requirements of DEMO still exceed those for ITER, e.g. for the plasma density.
Also being investigated are magnetohydrodynamic (MHD) instabilities, which limit the operating range. Active control of these is being achieved in ASDEX Upgrade primarily by means of electron cyclotron resonance heating.
One important objective is to develop plasma states suitable for a reactor-compatible wall clad with tungsten: Since 2007 ASDEX Upgrade is run with a first wall completely clad with tungsten.
Moreover, personnel from the division are collaborating on the JET (Joint European Experiment) at Culham, UK. Here the emphasis lies on the transfer of results from ASDEX Upgrade to JET for investigating the scalability of these results to ITER and DEMO.