Modeling of Excitation by Heavy Particles in Pure H2 Discharges at High E/N

V. Stojanović and Ž. Nikitović Institute of Physics, University of Belgrade, P.O.B. 68, 11080 Belgrade, Serbia

Received: September 21, 2011; In final form: January 10, 2012

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H α emission profiles were calculated for the high E/N (electric field E to gas density N ratio) Townsend discharges in pure hydrogen. Heavy particle collisions including the fast neutrals and interactions with the cathode surface are also included. The basic data were chosen to be in accordance with those used by Phelps. Monte Carlo simulation technique employing null collision method was used to follow electrons and heavy particles between collisions with H2 or with surface for the conditions of a high E/N. Trajectories of reaction fragments are followed after the collision until their neutralization or thermalization down to the threshold of H α excitation. We obtained spatially resolved emission profiles and the Doppler broadened line profiles for the conditions of the experiment of Petrović and Phelps. Intensity of the Doppler profile wing showing H α emission of particles emerging from the cathode direction is obtained assuming that the reflection coefficient of the fast H atoms depends on the incident angle and on energy of the incident particle.

DOI: 10.12693/APhysPolA.121.622 PACS numbers: 51.10.+y, 52.20.Hv, 52.65.Pp, 52.77.-j