KINETIC INVESTIGATION OF AVALANCHE AND STREAMER DEVELOPMENT.

Results are presented from simulations of the evolution of an electron avalanche in a uniform electric field and its transition into streamers. A Monte Carlo technique has been used to describe the dynamics of the electrons in phase-space taking into account collective effects due to the space-charge electric field. This field is obtained from Poisson's equation assuming cylindrical symmetry. The role that the space-charge field, the electron velocity distribution, and photoionization play in the development of an avalanche, and in the formation of streamers are considered. The results are for nitrogen at applied electric field-to-gas density ratios (E/N) of 3 multiplied by 10** minus **1**5V-cm**2 and 1 multiplied by 10** minus **1**4V-cm**2 and for background neutral densities of 1 multiplied by 10**1**9 cm** minus **3 and 2. 45 multiplied by 10**1**9 cm** minus **3.