The Role of Sodium Halide in Improving the Plasma Properties of Mercury-Sodium Mixture Under Atmospheric Pressure

Abstract

The model used in this study includes theoretical calculations and numerical simulation data to determine the impact of cathode surface temperature (Tw) on the current densities in plasma (electrons, ions, and emitted electrons) in arc discharge plasma. The goal of the study is to improve lamp lighting, increase the brightness ratio, and enhance overall performance. The model employed in this study is computational and numerical, utilizing simulations to predict the effects of cathode surface temperature on various plasma parameters. The study assumes thermal equilibrium in the plasma. The temperature change of the electrons was studied according to the change in temperature of the cathode surface inside the plasma. A mixture of mercury and sodium (0.1, 0.01 and 0.001 mol.) was used in varying proportions, and the effect of changing the concentration and choosing the optimal temperature to increase lighting efficiency and brightness was examined. Plasma physics, especially arc discharge, forms a strong foundation for lighting technology in gas discharge lamps. The effect of ionization and excitation processes near the cathode surface was studied, and it was observed that as the temperature increases As a consequence, the current densities (jᵢ, jₑ, and jₑₘ) also increase, leading to a rise in the plasma current density (j). By using varying concentrations of sodium (Na) with mercury gas (Hg), a noticeable increase in ionization processes and electron emission is observed as the halide concentration in the mixture increases. Choosing 10 V and 40 V as a method to study the effects of both low and high voltages on plasma properties. When applying different voltages, 10 volts and 40 volts, it is noted that reducing the applied voltage to 10 volts reduces the electric field and the energy supplied to the electron to release it, which affects the rates of ionization, collision, and thermal emission in the plasma.