High-density relativistic electron beam propagation in gas

The ionization front induced by a relativistic high-density electron beam in gas was studied in 1D approximation. We extended the approach of [1] to the relativistic beam energies and calculated the ionization front velocity for a wide range of beam energies and gas densities. The asymptotic expressions for the ionization front velocity were found in the limits of small and large gas density. The estimated amplitude of the front velocity is in a good agreement with the experimental data [2] where it was shown that the ionization front velocity is much smaller than the beam electron velocity. We also present the results from the ionization front computer simulation using a 1D PIC code with field ionization. [1] S. I. Krasheninnikov, B. K. Frolov, Phys. Plasmas \textbf{13} 033101 (2006) [2] D. Batani, S. D. Baton, M. Manclossi, \textit{et al}, Phys. Rev. Lett. \textbf{94, }055004 (2005) This work was supported by DOE/NNSA-UNR under grant DE-FC52-01NV14050.