Modelling low and middle pressure gas discharge for lighting applications

Summary form only given. The incandescent lamp takes a very large place in lighting applications; but nowadays, the use of electrical discharge lamps is growing up very rapidly. Apart from lighting, these lamps may found a lot of applications in several areas like water sterilization processes. The most used and well known electrical discharge lamp is made of mercury argon mixture and is commonly called a fluorescent lamp. But due to environmental considerations we try to find some others systems with a view to replace mercury in the mixture. One of them may be to use a single or mixtures of rare gas(es) (already done in neon signs or in xenon lamps). Our work is aimed to be a contribution to a better knowledge of this alternative. We work under low and middle pressure (about few Torr to hundred Torr) and the electron temperature is about 10/sup 4/ K. In such conditions the system is far from local thermodynamic equilibrium conditions so to describe the discharge, we need a collisional radiative model. The model is based on the SCCR code developed previously in our team (Zissis, 1990). The new settings allow us to study especially discharges composed with a single gas or a binary mixture of gas. In this mixture, we have tried to minimize simplifications concerning the buffer gas. We have also gathered some basic data which enable us to reproduce the discharge as well as we can and as realistically as possible. We choose to use rare gases and mixtures that appear to be interesting from our point of view. It means neon, argon, xenon, argon-neon and neon-xenon. The gas mixture is chosen in order to agree with Penning ionization conditions. We also try to take into account as many excited levels as permitted by our established database. In this communication, we present physical, electrical and radiative properties of such discharges.