MODELING OF THE OBSERVED PARTICLE AND HEAT FLUXES IN THE X-POINT REGION IN JET

Particle and heat fluxes, deduced from experimental CCD camera and magnetic measurements in the upper X-point region during Ohmic and auxiliary heated discharges in JET have been analysed. Modelling of the particle and heat transport processes at the edge of the plasma with Monte Carlo orbit following calculations agrees well with the observations. The importance of the finite orbit effects in low collisionality plasmas is assessed. The convection by plasma ions is found to play a very important role in the heat transport from the plasma to the wall.