Effect of the dome on divertor performance in ITER

The effect of variation of the divertor geometry in ITER is re-evaluated with the recently developed non-linear model of the transport of the neutral particles, taking into account neutral–neutral and molecule-ion collisions. The importance of the ‘dome’ for the neutral gas compression in the divertor is confirmed. Unlike earlier studies with a linear model of neutral transport, the present results show only a weak sensitivity of the divertor performance to the details of the divertor shape.