Exploring the Vibrational and Rotational Temperatures of a DBD Plasma Jet for Wound Healing

Due to their low gas temperatures, non-thermal, dielectric barrier discharge (DBD) finds frequent applications in wound healing and sterilization. Reactive nitrogen and oxygen species in the plasma play a vital role in this process. The concentration of these radicals is dependent on the plasma’s operating conditions (e.g. applied voltage and gas flow rates). Radicals’ vibrational and rotational temperatures play a vital role in wound healing and are required to find an optimized plasma operating condition for the wound healing process. The current project aims to measure the plasma temperatures (vibrational, rotational, and electronic) for a multi-electrode torch. The emission spectrum for various electrodes of the plasma torch was captured at various operating conditions. For this purpose, an Ocean Optics UV-IR spectrometer in conjunction with SPECAIR was used to estimate the vibrational, rotational, and electronic temperatures of the plasma. For this experiment the multi-electrode plasma torch was operated at various conditions by changing the outer electrodes, gas flow rates (helium 20-40 slpm), and input applied voltages (5kV-10kV and 20-40 kHZ). Experimental results reveal that both plasma vibrational and rotational temperatures $(\sim 500\mathrm{K}700\mathrm{K})$ were dependent on the measuring position from the plasma exit at identical operating conditions. No significant change in electronic temperatures $(\sim 2800\mathrm{K}$ – 3000K) was observed for all conditions. Detailed results are included in this paper.