Influence of gas discharge parameters on emissions from a dielectric barrier discharge excited argon excimer lamp

Abstract

Influence of gas discharge parameters on emissions from a dielectric barrier discharge excited argon excimer lamp. S Afr J Sci. 2011;107(11/12), Art. #581, 7 pages. http:// dx.doi.org/10.4102/sajs. v107i11/12.581A dielectric barrier discharge excited neutral argon (Ar I) excimer lamp has been developed and characterised. The aim of this study was to develop an excimer lamp operating at atmospheric pressure that can replace mercury lamps and vacuum equipment used in the sterilisation of medical equipment and in the food industry. The effects of discharge gas pressure, flow rate, excitation frequency and pulse width on the intensity of the Ar I vacuum ultraviolet (VUV) emission at 126 nm and near infrared (NIR) lines at 750.4 nm and 811.5 nm have been investigated. These three lines were chosen as they represent emissions resulting from deexcitation of excimer states that emit energetic photons with an energy of 9.8 eV. We observed that the intensity of the VUV Ar 2 * excimer emission at 126 nm increased with increasing gas pressure, but decreased with increasing excitation pulse frequency and pulse width. In contrast, the intensities of the NIR lines decreased with increasing gas pressure and increased with increasing pulse frequency and pulse width. We have demonstrated that energetic VUV photons of 9.8 eV can be efficiently generated in a dielectric barrier discharge in Ar.