POLOIDAL FLUX REQUIREMENT - ANALYSIS AND APPLICATION TO THE IGNITER CONFIGURATION

The definitions and correlations existing between different terms used by physicists and engineers are clarified in order to deal with the a ssessment of the poloidal flux requirement in a fusion experiment. The theoretical formulation of both the Faraday and the Poynting methods, for the internal flux evaluation, is briefly reviewed. Heuristic expr essions that allow estimates of internal flux consumption are reported for the specific case of an ignition experiment represented by the Ig nitor configuration. The analytical and heuristic results for both int ernal and external poloidal flux requirements are checked against nume rical evaluations carried out by using the TSC transport and magnetohy drodynamics code and the TEQ equilibrium code. A fairly good agreement between the different estimates is found. This suggests that simple h euristic expressions can be used to evaluate the poloidal flux require ment of future experiments, even if a detailed simulation of the plasm a current penetration process is strongly recommended to correctly ass ess and optimize the resistive poloidal flux consumption. Finally, the poloidal flux requirement for different plasma scenarios in the Ignit or experiment is compared with the magnetic flux variation that can be delivered by the poloidal field system.