Modelling of tungsten and beryllium dust in ITER

Production of dust particles during tokamak operation is a critical issue for magnetic confinement fusion. Their introduction into the reactor can have serious consequence on its performance and can constitute a safety issue. For these reasons the study of dust particles in tokamaks is crucial. Direct experimental observations of such particles that would give insight into their behaviour are quite challenging. In this context, numerical modelling of the relevant phenomena, plays a key role for better understanding the transport mechanisms of dust in tokamaks. In this work the dust transport code, Dust in tokamaks (DTOKS), is used to investigate how far tungsten and beryllium dust grains can penetrate into the ITER plasma. We simulate W and Be dust grains, with radii rd = 1–100 µm, and injection velocities, vinj = 1–100 ms−1, ejected from three different locations of the ITER vessel. It was found that particles with radius larger than 10 µm, with vinj = 10 m s−1, can survive long enough to reach the separatrix. Furthermore, the important roles of the initial injection velocity and injection location have been highlighted. (paper)