Photoionization Current by Vacuum Ultraviolet Light in N2/O2 Mixtures

Abstract

Measurement of photoionization current is carried out in N2/O2 mixtures using a gas cell, which is made up an eccentric cylinder electrode. A deuterium discharge lamp with MgF2 window is used for vacuum ultraviolet source. The photon energy of the VUV is changed by CaF2 and quartz filters. The photoelectron current emitted from the surface of electrodes is observed in pure N2 gas. On the contrast, it is confirmed that photoionization current increased in the gas cell with an increase in the partial pressure of O2 in N2/O2 mixtures. Such current is also found in UV region. These facts prove certain generation processes of charged particles by photo ionization of NO which is formed through the recombination from dissociated O and N atoms by the VUV absorption. However, another result suggests a possibility of a certain charged particle production process through the interaction between N2 and photodissociated O atom. © 2004, The Institute of Electrical Engineers of Japan. All rights reserved.