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 typical
$V$
–
$I$
characteristics 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 from
$B$
to
$X$
state. 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+, Kr
$_{2}^{+}$
, 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.