Optimization of Spatial Parameters of a 2.45-GHz Atmospheric Pressure Cold Plasma Jet: Comparison Between Multiphysics Simulation and Experimental Results

In this article, the optimization of spatial parameters of a 2.45-GHz atmospheric pressure plasma jet (APPJ) at different operational parameters has been done. For this purpose, simulations and experiments have been carried out to investigate the spatial dimensions of the microwave cold plasma jet generated from the device. To achieve this, the plasma discharge behavior and jet formation have been studied at different working gas flow rates and input microwave power. The 3-D simulations have been carried out by using the plasma module and electromagnetic wave module of COMSOL Multiphysics v. 5.5. Experimental validation was achieved and simulated spatial dimensions of plasma jet showed good correspondence with the experimental results. Simulated variations of jet length and diameter with gas flow rate and applied power matched closely with experimental results. Intrinsic plasma parameters, such as electron temperature (
$T_{e}$
) and number density (
$n_{e}$
), were also obtained with the simulation model and compared with experimental findings based on optical emission spectroscopy (OES) results and
$T_{e}$
values matched well in both cases.