Barium Atom and ion densities in a fluorescent lamp obtained from measurements and computer simulations

The measurements and simulation of barium atom and ion number densities in low and high frequency fluorescent lamp are presented. Barium emitted from the electrode surface has a strong interaction with the local plasma. The distributions of number densities for barium atom and ion depend mainly on the discharge conditions, such as the temperature of the operating electrode, and the number densities and distributions of other species (e.g. argon and mercury). A Monte Carlo computer simulation for the distribution of Ba{sup +} number density is described and the results from the simulation are compared to the experiment results obtained by absorption spectroscopy. A good agreement is reached between the simulation and the experimental Ba{sup +} distribution.