Predictions of high $Q_{DT}$ in ITER H-mode plasmas

Time-dependent integrated predictions of performance metrics such as the fusion power P$_{DT}$, Q$_{DT}\equiv$ P$_{DT}/$P$_{ext}$, and alpha profiles are presented. The PTRANSP code (see R.V. Budny, R. Andre, G. Bateman, F. Halpern, C.E. Kessel, A. Kritz, and D. McCune, Nuclear Fusion {\bf 48} 075005, and F. Halpern, A. Kritz, G. Bateman, R.V. Budny, and D. McCune, Phys. Plasmas {\bf 15} 062505) is used, along with GLF23 to predict plasma profiles, NUBEAM for NNBI and alpha heating, TORIC for ICRH, and TORAY for ECRH. Effects of sawteeth mixing, beam steering, beam shine-through, radiation loss, ash accumulation, and toroidal rotation are included. A total heating of P$_{ext}$=73MW is assumed to achieve H-mode during the density and current ramp-up phase. Various mixes of NNBI, ICRH, and ECRH heating schemes are compared. After steady state conditions are achieved, P$_{ext}$ is stepped down to lower values to explore high $Q_{DT}$. Physics and computation uncertainties lead to ranges in predictions for P$_{DT}$ and Q$_{DT}$. Physics uncertainties include the L$\rightarrow$H and H$\rightarrow$L threshold powers, pedestal height, impurity and ash transport, and recycling. There are considerably more uncertainties predicting the peak value for Q$_{DT}$ than for P$_{DT}$.