The WEST tokamak operates long pulses up to 1337 s in a full-tungsten (W) environment, anticipating challenges of next-generation fusion devices. Recent predict-first long pulse experiments, conducted based on High-Fidelity Plasma Simulator (HFPS) simulations, culminated in a new record pulse and validated the modeling framework. In an electron-heated, via the Lower-Hybrid Current-Drive (LHCD), fully non-inductive regime with W impurities, overall performance in terms of triple product remains limited, and off-axis current drive can trigger core q-profile reversal, degrading MHD stability. The new 3 MW/1000 s Electron Cyclotron Resonance Heating and Current-drive (ECRH/ECCD) system under integration offers localized heating and current drive to mitigate these limits. In the present paper, building on the validation of the HFPS, a predict-first exercise is performed to prepare WEST long pulse operation with additional ECRH/ECCD. Simulations indicate that applying on-axis ECCD to an LHCD-heated plasma enhances the stored energy content by 10%, improves the plasma core stability, and provides similar levels of non-inductive current than LHCD alone. Moreover, ECCD modifies the LHCD deposition location, offering significant q-profile tailoring capabilities. Off-axis ECCD operation provides access to advanced scenarios: raising the central q above 2 or suppressing turbulence sufficiently to trigger internal transport barriers when combined with strong core heating, yet with increased risk to core tearing instability. These results outline strategies for combined LHCD/ECRH/ECCD operation in WEST and stress the importance of the ECCD launching angle optimization for performance and stability.
Stabilization of neoclassical tearing mode by ECCD and its evolution simulation on JT-60U tokamak