EFFECT OF THE MAGNETIC-FLUX GEOMETRY OF A POLOIDAL DIVERTOR ON THE PROFILES AND PARAMETERS AT THE TARGET

The effect of the magnetic flux geometry of a poloidal divertor on the profiles and parameters at the divertor target is described by means of a simple model. Because of the magnetic flux expansion near the X-point, exponential profiles at the midplane of the tokamak are transformed into Gaussian profiles at the target. When the angle of incidence of the field line onto the target is considered, the possible existence of a maximum in the flux onto the target away from the magnetic separatrix appears naturally, in agreement with experimental results.