Experimental evidence of Penning ionization role in a low pressure direct current nitrogen glow discharge

¹ Departamento de Física, Instituto Tecnológico de Aeronáutica, Centro Técnico Aeroespacial, 12228-900 São José dos Campos, Brazil
² Laboratório de Aferição e Instrumentação Meteorológica, Divisão de Meio Ambiente e Estudos Climáticos, Instituto Nacional de Pesquisas Espaciais, 12630-000 Cachoeira Paulista, Brazil
³ Laboratoire de Physique des Gaz et des Plasmas, Associé au CNRS, UMR 8578, Bât. 210 Université Paris XI, 91405 Orsay Cedex, France

Corresponding author: jayr@fis.ita.br

Received: 17 January 2003
Revised: 10 October 2003
Accepted: 18 December 2003
Published online: 22 March 2004

Abstract

On the basis of experimental measurements of the electric field (which varies from 5 to 60 V/cm) and the N-atom relative density variation (one order of magnitude), mechanisms of ionization and dissociation in direct current glow discharges are discussed for pressures ranging from 0.5 to 5.0 torr and current between 1 and 50 mA. It is shown that: (i) at low pressure (E/N > 40 Td) ionization is governed by electronic impact and Penning reactions; (ii) at high pressure (E/N < 40 Td) the ionization is mainly governed by Penning reactions.