Dust: A new challenge in nuclear fusion research?

Small particles (dust) exist in magnetic confinement fusion devices. Their origin is due to plasma-surface interactions. Dust particles may contain si gnificant amounts of hydrogen isotopes, 50% of which will be tritium in fut ure devices. It is important to assess and understand the processes by whic h dust is formed and by which it interacts with the fusion device and its p lasma. Dust may be a safety hazard due to its high chemical reactivity and due to the mobile tritium inventory. Dust may influence the plasma performa nce and the operation of fusion devices. The radioactive decay of tritium i ncorporated into carbonaceous dust may lead to its charging and to the form ation of a nuclear induced plasma associated with levitation and transport of dust inside the vacuum vessel. Some important aspects of dust in fusion devices will be discussed, making use of information from the area of plasm a-surface interactions in fusion devices and from the field of dusty plasma research. (C) 2000 American Institute of Physics. [S1070-664X(00)01410-5].