Abstract
The understanding and control of plasma-wall interactions is of paramount importance for the successful deployment of nuclear fusion energy. Plasma-facing materials in ITER will be exposed to unprecedented heat and particle fluxes, which can currently be reached neither in fusion devices nor in plasma-material interaction facilities. This statement has driven the development of powerful linear plasma devices- Pilot and Magnum-PSI, uniquely capable of producing plasma conditions similar to those expected in the divertor of ITER both steady-state and transients.
Those devices provide a cost-effective approach to the fundamental understanding of plasma-surface interactions under high heat and particle fluxes, with a good access to the plasma-material interaction zone for diagnostics and sample manipulation. They are worldwide unique in their abilities to reproduce and even exceed the heat (>30MW.m-2) and particle fluxes (up to 1025m-2s-1) expected in the divertor of ITER. In addition, combined steady-state/pulsed operations are possible to study the effects of transient heat loads on a plasma-facing surface, similar to those expected during ELMs. Heat loads in excess of 1GW.m-2 can be generated with a repetition rate of 10Hz, and pulse duration of about 1ms.
In this talk, a description of Magnum-PSI will be given with an emphasis on the flexibility of the target system allowing a wide variety of experiments to be carried out. We will also discuss how those devices can help assessing some of the urgent plasma-material interaction issues. In particular, the talk will focus on the occurence of surface modifications under high particle fluxes and their influence on the resilience of tungsten to transient heat loads.
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