Theory of the scrape-off layer width in inner-wall limited tokamak plasmas
We develop a predictive theory applicable to the scrape-off layer (SOL) of inner-wall limited plasmas. Using the non-linear flattening of the pressure profile as a saturation mechanism for resistive ballooning modes, we are able to demonstrate and quantify the increase of the SOL width with plasma size, connection length, plasma beta, and collisionality. Individual aspects of the theory, such as saturation physics, parallel dynamics, and system size scaling, are tested and verified using non-linear, 3D flux-driven SOL turbulence simulations. Altogether, very good agreement between theory and simulation is found.
0029-5515_54_4_043003.pdf
Publisher's version
openaccess
741.97 KB
Adobe PDF
95d08847578e85e02ddb826c9fbd4c0a