Influence of massive material injection on avalanche runaway generation during tokamak disruptions

  title={Influence of massive material injection on avalanche runaway generation during tokamak disruptions},
  author={L. Hesslow and Ola Embreus and Oskar Vallhagen and T{\"u}nde F{\"u}l{\"o}p},
  journal={Nuclear Fusion},
In high-current tokamak devices such as ITER, a runaway avalanche can cause a large amplification of a seed electron population. We show that disruption mitigation by impurity injection may significantly increase the runaway avalanche growth rate in such devices. This effect originates from the increased number of target electrons available for the avalanche process in weakly ionized plasmas, which is only partially compensated by the increased friction force on fast electrons. We derive an… 

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