A physical model of calculating the pellet ablation rate in tokamak fueling was proposed, which was combined with the 1-D transport model to develop the 1.5D pellet ablation code. Using the parameter of ITER-FEAT, the pellet ablation rate of radius 6mm with initial injection speed of 2000m•s-1 when injecting from low field side was calculated. The results show that the ablation rate first increases gradually over time, then decreases rapidly because of decrement of pellet radius, the maximum ablation rate is about 6×1026s-1, the total penetration depth is about 0.45m. This result is consistent with that gained from the neutral gas shielding model (NGS), and it proved the validity of the code. At the same time, the calculation result indicate that, for the reactor grade tokamak such as ITER, using conventional pellet injection method, the penetration depth is small enough so that the core plasma fueling cannot be achieved although the injection speed is 2000m•s-1. Therefore in order to raise the plasma fueling efficiency, other effective pellet injection scenario must be chosen.
