Numerical Scaling with the COREDIV Code of JET Discharges with the ITER-Like Wall: Numerical Scaling with the COREDIV Code of JET Discharges with the ITER-Like Wall

After the code parameters have been fixed by the numerical modeling of a well diagnosed JET pulse, the electron density and the input power have been changed, resulting in 4 density scans (< n(e)> in the range 3.8 - 8.2 x 10(19)m(-3)) at P-in = 17, 22, 27, 32 MW. At any given power level, W flux decreases with increasing < n(e)> as a consequence of the decrease in T-e at the target plates. Also the W concentration in the core (c(W)) decreases, but this not necessarily leads to reduced core radiation. Indeed, while at high P-in the core radiation decreases with density, at low P-in it increases. At high < n(e)> the increase in the input power leads to enhanced P-rad, leaving, however, nearly unchanged the power radiated fraction f(rad). Indeed, the increase in f(rad) with P-in is observed only at low < n(e)>, up to a level of about f(rad) = 0.4. These numerical results, linked to the non-linear self-consistent physics of W production and transport, suggest the best conditions are achieved when the level of the electron density is adapted to the level of the available P-in. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim