Microwave air plasma source at atmospheric pressure: Experiment and theory

Abstract

An experimental and theoretical investigation of the axial structure of a surface wave (2.45 GHz) driven atmospheric plasma source in air with a small admixture (1%) of water vapor has been performed. Measurements of the gas temperature and of the intensities of the O(777.4 nm), O(844.6 nm), and O(630 nm) atomic lines and the NO(γ) molecular band versus input power and axial position were carried out. Amplitude and phase sensitive measurements have also been performed to derive the surface wave dispersion characteristics. The experimental results are analyzed in terms of a one-dimensional theoretical model based on a self-consistent treatment of particle kinetics, gas dynamics, and wave electrodynamics. The predicted gas temperature and emission line intensities variations with power and axial position are shown to compare well with experiment. “Hot” excited O atoms (with kinetic energy ∼2 eV) have been detected.

Bactericidal Effects against S. aureus and Physicochemical Properties of Plasma Activated Water stored at different temperatures

“…Atomic oxygen is a chemically reactive species which can cause damage in biological molecules36. Atomic oxygen is readily converted into other reactive oxygen species, such as O 3 , ·OH and H 2 O 2 , due to high activity through chemical reactions373839. Nitrites, nitrates, S-nitrosothiols and nitrosamines are metabolites of NO and mediators of the related cytotoxic effects, namely inhibition of mitochondrial respiration DNA damage leading to gene mutation, protein alteration and loss of function, necrosis, and apoptosis40.…”

Assessment of the Physicochemical Properties and Biological Effects of Water Activated by Non‐thermal Plasma Above and Beneath the Water Surface

“…Atomic oxygen can be readily converted into other reactive oxygen species (such as, O 3 , . OH and H 2 O 2 ) due to its high activity through chemical reactions . O 3 can interfere with cellular respiration and is mainly used for the disinfection of water .…”

On the plasma-based growth of ‘flowing’ graphene sheets at atmospheric pressure conditions

“…Given the fact that, under the conditions of interest, the main role of the electrons is to absorb microwave power and to transfer it to the heavy particles, we further assume δ = 0.9, which is a typical value for atmospheric pressure conditions, and ~10% energy in radiation and dielectric losses. The approach used has been validated in a series of extensive experimental and theoretical studies [34,[49][50][51][52][53][54].…”

“…The reference point z = 0 corresponds to the launcher position. The measured wall temperature axial profile (see figure 4(b)) as a boundary value of the gas temperature was fitted by an analytical expression and used as an external parameter in the numerical calculations [49]. The changes of wall temperature due to the external heating are shown by the broken line in the figure.…”