Differential nature of inelastic collisions facilitating runaway electron generation in weakly-ionized plasmas
We report extention of the Dreicer generation theory to situation where the small energy exchange no more predominates. In weakly-ionized plamsas, the Dreicer mechanism can be severely underestimated due to the broken assumption of dominant small energy exchange. This Letter numerically demonstrates that the differential nature of inelastic collisions facilitates the Dreicer generation by developing the new Fokker-Planck-Boltzmann operator of electron-hydrogen atom collisions based on experimental data. This work is envisaged to predict runaway electron generations in future fusion reactors.