Impurity Transport Studies In Tokamak Edge Plasmas Using Visibe Imaging

Understanding impurity transport in the scrape-off layer (SOL) of tokamak plasmas is a necessary piece of developing the physics basis for designing next-generation reactors. A system for inferring impurity transport parallel and perpendicular to local magnetic field lines has been developed on Alcator C-Mod using gas-injection "plumes". In this system, impurity gas is injected at a fixed position in the SOL via a reciprocating fast-scanning probe, and the resulting emission is imaged. In this paper visible light emission patterns from C+1 and C+2 ions are presented.