Predictive Simulations of Toroidal Momentum Transport in JET

Predictive simulations of temperature and toroidal momentum profiles were made using the new version of the Weiland model. Here the toroidal momentum transport due to ITG/TE modes is calculated self-consistently and the momentum flux contains a diagonal outward term ($\Gamma_{\rm tor}\sim dV_{\rm tor}/dr$) and non-diagonal pinch terms (Weiland, Nordman, EPS 2006, P2.186). The model predicts that the Prandtl number $\chi_{\rm tor}/\chi_{\rm i}$ is about 1/3 for typical tokamak parameters, in rough agreement with recent results from JET. Predictive JETTO simulations have been performed for JET L-mode, H-mode and hybrid discharges at low and high density. Temperature profiles were well reproduced. Simulations performed with only the diagonal part of the momentum transport under-predicted the toroidal momentum. With the non-diagonal terms included a slight over-prediction of the toroidal momentum was obtained. This may be reduced by including effects of collisions on ITG/TE mode driven momentum transport.