Consequences of a reduction of the upstream power SOL width in ITER

The effect of a hypothetical reduction of the SOL power width on the performance of the ITER divertor is analyzed using the SOLPS4.3 code. A reduction of this width by a factor 3 (down to 1.2 mm) is found to increase the peak power load only by a factor 1.6 because power dissipation in the partially detached divertor plasma is enhanced. The operating window is smaller, but still exists at 10 MW/m2 power load. Full alpha particle power is recovered if the allowed peak power load is a factor 1.5 higher, albeit at reduced Q which still remains above Q = 10.