Non-self-sustained discharge in nitrogen with a condensed dispersed phase

A non-self-sustained discharge in nitrogen with a condensed dispersed phase is studied experimentally for the first time under atmospheric pressure at room temperature. It is shown that macroparticles strongly affect the curr ent-voltage characteristics as well as the stability of the discharge proce ss. A numerical simulation of dust particle charging in nitrogen is carried out at room temperature and cryogenic temperatures under continuous medium conditions. It is shown that a considerable charge is accumulated at macro particles in the nitrogen beam plasma. As the gas temperature decreases, th e charge of macroparticles in nitrogen increases, while in argon their char ge decreases. For this reason, the Coulomb interaction parameter for dust p articles in nitrogen increases strongly upon a transition from room to cryo genic temperature, while in argon this parameter decreases. It is also show n that the characteristic time of dust particle charging is shorter than 1 mus for a beam current density of 90 muA/cm(2), while the neutralization of the charge takes milliseconds. Possible mechanisms of the influence of the dust component on the characteristics of non-self-sustained discharge are considered. (C) 2001 MAIK "Nauka/ Interperiodica".