Low-pressure plasma discharge of Ar/N2/CH4 ternary mixture: experimental simulation of Titan's atmosphere

15th International Congress on Plasma Physics; 13th Latin American Workshop on Plasma Physics

Salazar-Flores, L.^1 ; Torres-Segundo, C.^2 ; Reyes, P.G.^2 ; Castillo, F.^3 ; Martinez, H.^4

Posgrado en Ciencias Fisicas, Universidad Nacional Autónoma de México, Avenida Universidad 1000, México D.F., 05000, Mexico^1

Facultad de Ciencias, Universidad Autónoma Del Estado de México, Instituto Literario 100, Centro, 50000, Toluca, Mexico^2

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, México DF, 04510, Mexico^3

Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de México, Apartado postal 48-3, Morelos, 62251, Cuernavaca, Mexico^4

关键词: Different pressures;    Experimental simulations;    Function of pressure;    Low pressure plasma;    Molecule reactions;    Optical emission spectroscopies (OES);    Ternary mixtures;    Titan's atmosphere;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/511/1/012055/pdf
DOI  :  10.1088/1742-6596/511/1/012055

来源: IOP

【 摘 要 】

A low-pressure DC plasma discharge sustained in a 85.0%N2-12.0%Ar- 3.0%CH4, 82.3%N2- 13.7%Ar- 4.0%CH4and 79.6%N2-15.4%Ar- 5.0%CH4ternary mixtures are studied. These plasmas were generated in the total pressure range of 0.5 to 10.0 Torr and power of 7 W. The diagnostic has been made by optical emission spectroscopy (OES) using a spectrometer. The principal species observed were: at 315.93, 337.13, 375.54, 399.84 and 405.94 nm for N2(C3Πu-B3Πg); at 354.89, 358.21, 376.16, 391.44 and 427.81 nm for N2+(B2Σ+u- X2Σ+g); at 381.06 nm for CH+(A1Π-X1Σ); at 392.08 nm for CN(B2Σ-X2Σ), at 428.15 nm for CN(B2Σ-A2Π) and at 708.87 nm for CN(A2Π-X2Σ); at 436.52, 592.34, 653.40, 667.73 and 708.32 nm for C2(A3Πg-X'3Πu; at 392.59 nm for C3(1Πu-1Σ+g); at 486.14 nm for H; at 486.13 and 656.27 nm for Hαat 657.80 nm for C+; at 739.23,751.47,763.51, 772.42, 794.82 and 811.53 nm for Ar. We present the behaviour of the bands and lines intensities as a function of the pressure and concentration of Ar, N2and CH4gases. Also, we display more quantitatively the ratios of intensities of N+2(391.44 nm), CN (392.08 nm), and H (486.13 nm) to that of the N2(337.13 nm) as function of pressure. The ratios show a slow decreasing behavior as a function of the pressure. Being the CH/N2ratio more highest and H/N2 ratio the lowest one. The variations of excited species at different pressures may change the subsequent chemical reactions in the gas phase significantly. The present results suggest that the ion-molecule and molecule-molecule reactions in the gas phase are likely to play a dominant role in the present pressures.