Alfvén wave forces, affecting the tokamak edge plasma in the presence of impurities or dust

Abstract
Dust particles appear on the edge of tokamak plasmas as a result of disruptions and plasma interactions with divertor plates, limiters, or blankets, as well as of pellet injections. It is shown that the presence of the dust impurities can lead to an effective decrease of the slow Alfvén wave absorption in the region. These waves are used for heating, current drive, and control of the low-to-high (L–H) confinement transition. Radio-frequency forces can also be strongly changed in the presence of dust particles.