Significance of Magnetic Shielding in the Ablation of a Solid Hydrogen Pellet in a Plasma

The magnetic field configuration in the vicinity of an ablating solid hydrogen pellet in a tokamak fusion plasma has been determined in a self-consistent manner, which indicates that the field lines are slightly bent from their unperturbed configuration. This gives rise to a slight decrease in the incident energy flux to the ablation cloud surrounding the pellet, and accordingly the pellet lifetime slightly increased over that predicted by the existing neutral ablation theories which do not consider magnetic shielding effects. However, due to many factors including the transients involved in the exclusion of residual magnetic field, significant decreases in the pellet ablation rates over those of the neutral ablation cloud models are not to be expected.