Optimization of Current Waveforms in ITER Correction Coils

The magnetic field in fusion reactors based on magnetic confinement must have a quite precisely defined map, in order to guarantee the expected performance. This is achieved in ITER using three sets of high field coils, plus an additional set of Correction Coils, aimed at correcting possible deviations from nominal performance of main magnets. Currents in these coils are chosen on the basis of desired plasma behavior, but possible advantages in terms of stored magnetic energy or power supply needs, or finally in terms of electromagnetic load on the reactor structure could be achieved by different choices of correction currents waveform. In this paper, possible performance criteria are defined and optimization of correction current is performed consequently.