Comparison of relativistic runaway electron avalanche rates obtained from Monte Carlo simulations and kinetic equation solution

New computer simulations of the relativistic runaway electron avalanche mec hanism were carried out to remove prior approximations and reassess the spa ce and temporal scales predicted by previous Boltzmann calculations. Two Mo nte Carlo techniques, a finite-difference solution, and a finite-volume sol ution of the kinetic equation for high-energy electrons were employed. Resu lts obtained for the length and time scales at sufficiently high electric f ields by the different methods are consistent with each other and with anal ytical estimates. The physical reason for the remaining discrepancy at smal l fields is discussed.