Applicability of optical emission spectroscopy techniques for characterization of Ar and Ar/O₂ discharges

Abstract

Here we explore the accuracy and applicability of two readily—available, low cost techniques: (a) a branching fraction method and (b) an extended corona method (ECM). A three dimensional Monte Carlo simulation was developed to obtain the electron energy distribution function, a necessary parameter in the extended corona model, and we discuss its dependence on oxygen percentage and discharge pressure. The experiment was conducted with a 13.56 MHz radio-frequency capacitive discharge in Ar and Ar with 10% and 20% O2. Absolute densities of argon resonant 1 s4 and metastable 1 s5 energy levels were calculated at various pressures, powers, and positions inside the resulting plasma using both methods. The ECM was also used for calculation of electron temperature and electron density under the same plasma parameters. Results showed that in pure argon, both methods present a good, inexpensive choice for plasma characterization.

Influence of the argon admixture on the reactive oxide species formation inside an atmospheric pressure oxygen plasma jet

“…It can be observed that the number density of positive ions increases at the higher argon percentages in O 2 /Ar gas mixture. This is owing to the higher cross section of momentum transfer for the atomic argon 56 , 57 , since collision energy of electrons decreases at the higher argon percentages. So, the recombination process between the electrons and positive ions will slightly occur in the plasma.…”

Formation of reactive chlorine species in Cl− solutions treated by plasma-supplied O atoms and some implications for biological inactivation functions

“…Spectral lines used in data analysis are noted in the figure. It mainly consists of OH(A-X) around 309 nm, N 2 (C-B) around 337 nm, N 2 + (B-X), OH around 616.2 nm and Ar emission lines around 696.5 nm, 763.4 nm and 811.6 nm [28][29][30][31]. The discharge state of a plasma jet plume can be influenced by the composition of working gas under the same discharge voltage.…”

Frequency-dependent electron power absorption mode transitions in capacitively coupled argon-oxygen plasmas

“…Gas discharges in argon-oxygen mixtures are often used for sputtering, deposition, to grow SiO 2 dielectric films on silicon, to etch photoresist and polymer films, as well as for sterilization of medical instruments and surface activation [10][11][12][13][14]. Over the years, the plasma properties of low-pressure argon-oxygen mixture CCPs have been studied extensively via modeling and numerical simulations as well as experimentally [15][16][17][18][19][20][21][22]. A reaction set for modeling argon-oxygen CCPs was introduced in [23] and the role of ionization, resonant and nonresonant charge-exchange collisions in the formation of the ion energy distribution at the electrodes was studied by Particle-in-Cell/Monte Carlo Collisions (PIC/MCC) simulations.…”