This paper presents the spatial characterization of Ar-N2 plasma induced by a helical cavity exci... more This paper presents the spatial characterization of Ar-N2 plasma induced by a helical cavity excited at 27 MHz and moderated pressure (400 Pa). The axial profiles of densities and gas temperature are determined through the emissions of the first positive (1+) and second positive (2+) systems of N2. Additionally, in case of pure argon plasma, the OH(A 2 Σ+→X2Π) emission
The BH A 1Pi --> X 1Sigma+ (0-0) transition was studied, in the emission mode, for gas tempera... more The BH A 1Pi --> X 1Sigma+ (0-0) transition was studied, in the emission mode, for gas temperature determination. Two typical conditions were used: doped diamond deposition conditions (H2/CH4/B2H6 99%:1%:0-100 ppm, from 2500 to 7550 Pa) and the vessel cleaning condition (H2, 85 Pa). Among the P, Q and R branches of the A 1Pi --> X 1Sigma+ (0-0) transition, only the unresolved Q branch is clearly observed in emission mode under the doped diamond deposition conditions, whereas the full rotational structure is observed under the vessel cleaning condition. We developed a simple simulation model based on calculation of the position of the rotational lines and the line intensities as a function of the temperature and profile width. After validation of the model using the R resolved structure from our data and from other authors' data, we applied this attractive method to a quick temperature determination in the unresolved Q branch simulation. The calculated temperatures were compared to other well established results obtained under the same conditions. Kinetics considerations led to the conclusion that the rotational temperature of the A excited states accounts for the gas temperature in both the above-mentioned conditions. It is also shown that two distinct rotational populations are present, suggesting the existence of two excitation mechanisms.
Optical emission spectroscopy in vacuum ultraviolet and UV spectral ranges is applied to study de... more Optical emission spectroscopy in vacuum ultraviolet and UV spectral ranges is applied to study densities, and vibrational and rotational temperatures of the N2 molecule in a nitrogen-argon (0-95% Ar) plasma sustained at a pressure of 400 Pa by a helical cavity supplied with a power of 28 W and an excitation frequency of 27 MHz. The spatial investigation of all
Properties both of the discharge and of the post-discharge region are studied through the so-call... more Properties both of the discharge and of the post-discharge region are studied through the so-called short-lived afterglow generated at 340 Pa by two similar coaxial cavities resonating at 433 and 2450 MHz. Simultaneous Raman Stokes scattering and optical emission spectroscopies are performed. The gas temperature profiles of the various regions are built up through exploitation of 0022-3727/31/19/025/img12 and 0022-3727/31/19/025/img13 rotationally
To gain an understanding of the processes responsible for the formation of the well-known short-l... more To gain an understanding of the processes responsible for the formation of the well-known short-lived afterglow (SLA) or pink afterglow of nitrogen, different diagnostic techniques are implemented in the afterglow of a 440 Pa microwave nitrogen discharge in a 3.8 cm diameter flow tube. Using the intracavity laser absorption spectroscopy technique, we measure the space-dependent absolute density of N2(A 3Sigmau+
This paper presents the spatial characterization of Ar-N2 plasma induced by a helical cavity exci... more This paper presents the spatial characterization of Ar-N2 plasma induced by a helical cavity excited at 27 MHz and moderated pressure (400 Pa). The axial profiles of densities and gas temperature are determined through the emissions of the first positive (1+) and second positive (2+) systems of N2. Additionally, in case of pure argon plasma, the OH(A 2 Σ+→X2Π) emission
The BH A 1Pi --> X 1Sigma+ (0-0) transition was studied, in the emission mode, for gas tempera... more The BH A 1Pi --> X 1Sigma+ (0-0) transition was studied, in the emission mode, for gas temperature determination. Two typical conditions were used: doped diamond deposition conditions (H2/CH4/B2H6 99%:1%:0-100 ppm, from 2500 to 7550 Pa) and the vessel cleaning condition (H2, 85 Pa). Among the P, Q and R branches of the A 1Pi --> X 1Sigma+ (0-0) transition, only the unresolved Q branch is clearly observed in emission mode under the doped diamond deposition conditions, whereas the full rotational structure is observed under the vessel cleaning condition. We developed a simple simulation model based on calculation of the position of the rotational lines and the line intensities as a function of the temperature and profile width. After validation of the model using the R resolved structure from our data and from other authors' data, we applied this attractive method to a quick temperature determination in the unresolved Q branch simulation. The calculated temperatures were compared to other well established results obtained under the same conditions. Kinetics considerations led to the conclusion that the rotational temperature of the A excited states accounts for the gas temperature in both the above-mentioned conditions. It is also shown that two distinct rotational populations are present, suggesting the existence of two excitation mechanisms.
Optical emission spectroscopy in vacuum ultraviolet and UV spectral ranges is applied to study de... more Optical emission spectroscopy in vacuum ultraviolet and UV spectral ranges is applied to study densities, and vibrational and rotational temperatures of the N2 molecule in a nitrogen-argon (0-95% Ar) plasma sustained at a pressure of 400 Pa by a helical cavity supplied with a power of 28 W and an excitation frequency of 27 MHz. The spatial investigation of all
Properties both of the discharge and of the post-discharge region are studied through the so-call... more Properties both of the discharge and of the post-discharge region are studied through the so-called short-lived afterglow generated at 340 Pa by two similar coaxial cavities resonating at 433 and 2450 MHz. Simultaneous Raman Stokes scattering and optical emission spectroscopies are performed. The gas temperature profiles of the various regions are built up through exploitation of 0022-3727/31/19/025/img12 and 0022-3727/31/19/025/img13 rotationally
To gain an understanding of the processes responsible for the formation of the well-known short-l... more To gain an understanding of the processes responsible for the formation of the well-known short-lived afterglow (SLA) or pink afterglow of nitrogen, different diagnostic techniques are implemented in the afterglow of a 440 Pa microwave nitrogen discharge in a 3.8 cm diameter flow tube. Using the intracavity laser absorption spectroscopy technique, we measure the space-dependent absolute density of N2(A 3Sigmau+
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Papers by C. Foissac