LIGHT IMPURITY RADIATION FROM THE ITER DIVERTOR PLASMA

The possible use of low Z materials for the ITER divertor plates is discussed. A non coronal radiation model has been developed which indicates that strong enhancement in the radiated power from the divertor may take place when finite confinement is considered. For carbon this leads to stable operating regimes at low electron temperature. It is shown that relaxation oscillations in the dynamical behaviour of impurity density and electron temperature are possible, and can lead to a large decrease in the gross erosion rate of the divertor plates for carbon and beryllium.