Diagnostics to Study Flow of Dust Particles in Scrape-Off Layer of Alcator C-Mod Plasmas

Dust transport and migration is not well understood in tokamaks. Furthermore, current numerical codes (DUSTT) have not been benchmarked with experiments. Interest in dust has increased over recent years as it may be a significant issue in machines with high duty cycles (ITER, DEMO) due to safety concerns. Measuring dust particle trajectories in the plasma can also give added information on Scrape-Off Layer (SOL) flows, since an important force on dust flow is a plasma drag force. In order to study dust particle trajectories in the SOL for different plasma densities and topologies, we have designed and installed a dust injector which injects Boron dust particles into the divertor region. The particles are viewed with a video camera. This provides us with a 2-D projection of the particle trajectories. For full 3-D trajectories we would need to install a second viewing camera. Initial data and results will be presented along with the successes and shortcomings of the diagnostic and future improvements.