The electron part of the heat flux calculated in section 8 was not calculated correctly, and this section should be replaced by the following.8. Additional heating associated with divertor biasingThe heat flux to the divertor plate surface is equal to [17]in the case of nearly normal incidence characteristic of the present MAST design. Here Wi is defined so as to make nu Wi equal to the ion energy flux on the plasma side of the sheath. In the unbiased case these fluxes have a common valueAssuming that the density and the temperatures do not change after the biasing (they are determined by the conditions in the upper part of the SOL, which is not affected by the biasing), and using equation (A2.4), one finds thatEven for e varphib/Te=10, corresponding to 100 V biasing voltage, the relative (with respect to q*) increase of the heat load is modest, about 50%.