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Title: Determination of vibrational and rotational temperatures in highly constricted nitrogen plasmas by fitting the second positive system of N{sub 2} molecules

Highly constricted plasmas are an active research area because of their ability to generate high activity of plasma beams, which exhibit potential in applications of material processing and film deposition. In this study, optical emission spectroscopy was used to study the highly constricted nitrogen plasma created at low pressure. The vibrational and rotational temperatures of molecules were determined by fitting the second positive system of nitrogen molecule. Under the conditions of the power densities as high as 7 ∼ 85 W/cm{sup 3} and the pressures of 2 ∼ 200 Pa, the determined rotational temperature was found to be relatively low, increasing from 350 to 700 K and the vibrational temperature keeping at ∼ 5000 K. The analysis of dissipated power revealed that ∼ 80 % of input power is dissipated for the nitrogen molecule dissociation and the creation/loss of ions at the tube wall, producing an as high as 10{sup 12} ∼ 10{sup 13} cm{sup −3} plasma with the nitrogen dissociation degrees of 2%∼15%. With the increase in the discharge pressure, more input power was found to be dissipated in the dissociation of nitrogen molecules instead of creation of ions, resulting in a higher density of radicals.
Authors:
; ; ; ; ;  [1] ; ;  [2]
  1. Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, and School of Physics and Opto-electronic Technology, Dalian University of Technology, Dalian 116024 (China)
  2. Science and Technology on Reliability and Environmental Engineering Laboratory, Beijing Institute of Spacecraft Environmental Engineering, Beijing 100094 (China)
Publication Date:
OSTI Identifier:
22488592
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 5; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DENSITY; DEPOSITION; DISSOCIATION; EMISSION SPECTROSCOPY; FILMS; MOLECULES; NITROGEN; PLASMA; POWER DENSITY; RADICALS