A 2-DIMENSIONAL KINETIC-MODEL OF THE SCRAPE-OFF LAYER

A two-dimensional (radius and poloidal angle), analytically tractable kinetic model of the ion (or energetic electron) behavior in the scrap e-off layer of a limiter or divertor plasma in a tokamak is presented. The model determines the boundary conditions on the core ion density and ion temperature gradients, the power load on the limiter or divert or plates, the energy carried per particle to the walls, and the effec tive flux limit. The self-consistent electrostatic potential in the qu asineutral scrape-off layer is determined by using the ion kinetic mod el of the layer along with a Maxwell-Boltzmann electron response that occurs because most electrons are reflected by the Debye sheaths (assu med to be infinitely thin) at the limiter or divertor plates.