Optical emission spectroscopy of CO₂ glow discharge at low pressure

Abstract

Optical emission spectroscopy was used to study the glow discharge of CO2 in the pressure range of 0.2 to 1.2 mTorr, power of 160 W and a flux of 35 psi. The emission bands and lines were measured using a monochromator in the wavelength range of 200 to 900 nm. The species observed were C2 (A3Πg – X'3Πu) at 435.7nm and (C'1Πg – b1Πu) at 369.2 nm; O2 (b1Σg+ ‐ X3Σg–) at 628.2; CO (a'3Σ ‐ a3Π) at 674.7 nm; O2+ (A2Πu ‐ X2Πg) at 339.3 and 289.2 nm; CO2+ (A2Π ‐ X2Π) at 353.2 nm; CO2 (1B2 – X1Σ+) at 391.7 nm; CO+ (A2Π – X2Σ) at 577.7 nm; and O3 (1B2 – X1A1) at 327.2 nm. We observed that the emission intensities bands have an almost constant behavior as function of the pressure in the range of 0.2 to 0.6 mTorr, followed by an increasing behavior. The electron temperature and ion density were determined by a double Langmuir probe. The electron temperature was found of 8.53 eV, and the electron concentration of 7.11 x 109 cm–3 at a pressure of 0.8 mTorr. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Preliminary Study of Thermal Treatment of Coke Wastewater Sludge Using Plasma Torch

“…The oxygen derived from CO 2 disintegration may be useful for industrial applications. The mechanism of CO 2 reacting with electron initiating the plasma reaction has been studied by former researches [27,28] . It can be mainly proposed into two kinds of reactions, as given below.…”

Stainless steel membrane distributor‐type dielectric barrier discharge plasma reactor for co‐conversion of CH4/CO2

“…For all the reactors, the emission peaks of CO 2 can be observed at ~335, 354, 375, and 435 nm, while the peak at ca. 414 nm could be assigned to the excited CO 2 + species (i.e., A 2 П u → X 2 П g ) 49,50 . Relevant peaks appeared at about 315, 390, and 431 nm could be assigned to the excitation of CH band (i.e., C 2 ∑ + → X 2 П, B 2 ∑ − → X 2 П, and A 2 Δ → X 2 П), suggesting the dissociation of CH 4 and the possible formation of higher hydrocarbons 46,50 .…”

“…X 2 П g ). 49,50 Relevant peaks appeared at about 315, 390, and 431 nm could be assigned to the excitation of CH band (i.e., C 2 Σ + ! X 2 П, B 2 Σ À !…”

Effects of radio frequency power on the microstructures and properties of plasma polymerized polypyrrole thin films

“…1 with identified peaks labeled. Details of these peaks are listed in Table 2 [43][44][45][46][47][48][49][50][51][52] where major peaks are transition of C-N, C-H, N-H and C2 bonds between different states. Accordingly, it seems that most carbon rings in pyrrole were "opened" by the plasma and thus the π-conjugate system was riven.…”