Characterizing a DBD Plasma Jet by a Langmuir Probe and Emission Spectroscopy at Atmospheric Pressure for Medical Applications

Recent research shows that reactive oxygen and nitrogen radicals entrained in a dielectric barrier discharge (DBD) plasma jet can accelerate the wound healing and wound sterilization process. The measurement of these radicals and plasma characterization will be beneficial for an optimized healing process. We are using emission spectroscopy in conjunction with SPECAIR to identify the multiple radicals’ peaks and extract information on plasma temperatures. Experiments show that the gas temperatures in our helium plasma jet vary between 30-40 C which is required for a safe plasma operation. The vibrational, rotational, electronic, and translational temperatures were found around 2500 K, 200 K, 200K, and 2500 K respectively. These conditions indicate a non-thermal DBD plasma that is essential for medical applications. The impact of adding oxygen/nitrogen (0.06% by volume) on various radicals and relevant plasma temperatures was also investigated. In addition, a Langmuir probe was used to estimate electron temperatures and electron number density. It was discovered that Langmuir probe applications in atmospheric pressure plasmas are more complicated as compared to subatmospheric plasmas. Our preliminary work indicates that electron temperatures are around 1eV that is currently being verified by repeating the experiment at other operating conditions. Detailed results will be discussed in the upcoming conference.