Automatic identification of the plasma equilibrium operating space in tokamaks

Abstract In order to identify the plasma equilibrium operating space for future tokamaks, a new objective function is introduced in the inverse static free-boundary equilibrium code FEEQS.M. This function comprises terms which penalize the violation of the central solenoid and poloidal field coils limitations (currents and forces). The penalization terms do not require any weight tuning. Hence, this new approach automatizes to a large extent the identification of the operating space. As an illustration, the new method is applied on the ITER 15 and 17 MA inductive scenarios, and similar operating spaces compared to previous works are found. These operating spaces are obtained within a few (∼ 3) hours of computing time on a single standard CPU.