Experimental and Numerical Characterization of Dielectric Barrier Discharge-Based Coaxial Kr/Cl2 Excilamp

In this article, experimental and numerical characterization of a dielectric barrier discharge (DBD)-based coaxial Kr/Cl2 excilamp excited by negative unipolar pulse has been carried out. The typicalV–Icharacteristics have been measured, which is further utilized to determine the average power deposited in the excilamp. It is found that the average power of 11.4 W has been deposited in the excilamp filled with the Kr/Cl2 mixture in the proportion of 99:1 at 100 mbar, creating microdischarges within the discharge region. The discharge mode of the excilamp is observed to be filamentary in nature. The intense emission of the 222-nm radiation is clearly shown in the spectra due to the transition of KrCl* excimer fromBtoXstate. The effect of different proportions of chlorine concentration (0.1%–5%) and total pressure of the Kr/Cl2 mixture (25–200 mbar) have been analyzed, which mainly influences the plasma chemistry during the discharge. It has been observed that a higher percentage of chlorine (1%–5%) with a total pressure range of 25–100-mbar results in a high peak intensity of 222-nm radiation. Other kinetic processes participating in excimer formation have also been analyzed by evaluating the density of electrons, Kr+, Kr₂⁺, Cl−, and Kr* created during the pulsed discharge, which has principally contributed to the formation of KrCl*excimer. This qualitative analysis is very useful for the design and development of suitable 222-nm excimer sources required for the effective inactivation of viruses (coronaviruses), bacteria, and pathogens.