Tokamak disruptions : investigations of symptoms and treatments

Plasma disruptions are a catastrophic loss of confinement that ultimately concludes with the release of the thermal and magnetic energy stored in the vessel containing the plasma. The threat of disruptions therefore factor into the development of fusion-grade tokamak reactors such as ITER. This work discusses the deleterious effects of disruption, particularly runaway electrons. Tokamaks are especially susceptible to runaway electrons because of their highly inductive nature. The lifetime of seed runaways are calculated and the likelihood for them to exponentiate is discussed. Strategies for alleviating the danger posed by disruptions are considered. The basic strategy, assuming a disruption is imminent, is to preemptively cool the plasma. ITER currently plans on deploying impurity pellets to safely radiate away the energy, so investigations of pellet heating and ablation are conducted.Physic