A noticeable reincrease in electron density was observed during the current-decaying phase of a pulsed Ar+H2(10%) discharge in a pressure range of 133∼800 Pa. It was experimentally verified by using laser-induced fluorescence and self-absorption methods that the reincrease appeared concurrently with the increase in a population density of the first excited state of H atoms. This phenomenon can be reasonably explained by a mechanism that such excited atoms increase due to dissociative recombination of ArH+ ions generated in the ionizing phase of the discharge and they are reionized by electron collisions. A proposed model, which was expressed both by rate equations of H atoms on the ground and excited states and three kinds of ions such as H+, H3+ and ArH+ and by a quasi-neutral equation of the plasma, can qualitatively explain these experimental results.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)