Optimization of the poloidal transformer of IGNITOR

One of the most critical parts of the high field tokamak IGNITOR is the inner poloidal transformer coil. This is due not only to the high stresses developed there but also to the large quantities of energy released and the resulting high temperature. It determines the overall cooling time of the machine and thus the maximum attainable number of pulses per year. An optimization based on a parametric study of the transformer was performed and configuration parameters were defined. Cooling time was the quantity to be minimized, with the maximum coil temperature and the maximum coolant outlet velocities as its main constraints. The cost of the cooling plant was also taken into account. The row of the conductors adjacent to the equatorial plane, which presents the highest stresses, was modeled and checked for maximum stresses. Thermal and magnetic loading, contact nonlinearity, and pretensioning were considered