Yuriy Mamontov2020-09-22 17:17 Hello, I impressed by your presentation. I also do Monte-Carlo simulations in my work, and I have several questions concerning your presentation. 1) Is your model self-consistent? As I understand, you use fluid mechanics equations for slow plasma electrons and a Monte-Carlo approach for fast runaway electrons. But do you take into account dynamics of an electric field during the streamer propagating? 2) What is the magnitude of an electric field near the tip of the cathode which you use in your calculations? 3) As I understand, on the surface of the cathode, you take into account photoionization and secondary ion-electron emission. But what about field emission of electrons? 4) From your work: there are two competitive mechanisms of the negative streamer propagation—photoionization and pre-ionization by fast electrons. Why they are competitive?? They act simultaneously, don't they? I understand that pre-ionization by REs gives much higher propagation rate of a streamer, but why photoionization and RE pre-ionization can't exist together? It would be interesting to see results of such a simulation. Thank you.