(a) Plots of B _T required versus fusion power redistribution parameter w for various models, showing that as the fusion deposition power moves away from the center, the required B_T increases for all models. (b) Plots of difference in required B_T relative to that of the original model used in Ref. [4], versus fusion power redistribution parameter w, indicating that as w increases, values of required B_T for ‘DC’, ‘H’, and ‘GB’ models are all improved with respect to those of original model and ‘GP’ model becomes less favorable. The values of B_T and delta B_T changing over actually occur around w = 0.45 before reaching 0.7.