Scaling of the scrape-off layer width in MAST L-mode plasmas as measured by infrared thermography

摘要

Introduction The power exhausted from a tokamak plasma is directed, via the scrape-off layer (SOL), towards plasma facing divertor targets that are designed to handle high heat fluxes. The width of the SOL is important for future device design since it plays a role in setting the magnitude of the parallel heat flux arriving at these surfaces and the distance that can be tolerated between the plasma edge and first wall materials. The well-established Eich equation [1,2] can be used to characterise the divertor heat flux profile as an exponential decay for the SOL width,λq, and a Gaussian spreading factor, S, due to diffusion around the last closed flux surface (LCFS) into the private flux region. The profile shape is given by: {formula}