Simultaneous measurement of nitrogen and hydrogen dissociation from vacuum ultraviolet self-absorption spectroscopy in a developing low temperature plasma at atmospheric pressure

Journal Article · Mon May 06 00:00:00 EDT 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4804369· OSTI ID:22162901

Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas ^[1]; Frank, Klaus ^[2]

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1. Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)
2. Erlangen Centre for Astroparticle Physics, Department of Physics, Friedrich-Alexander University at Erlangen - Nuernberg, 91058 Erlangen (Germany)

We demonstrate a method for determining the dissociation density of N and H atoms present in a developing low temperature plasma, based on the emission and self-absorption of vacuum ultraviolet radiation produced from the plasma. Spark plasmas are produced via pulsed discharge in N{sub 2}/H{sub 2} mixtures at atmospheric pressure, where information on the dissociated densities of the constituent gas molecules is desired without employing invasive diagnostic techniques. By analyzing the self-absorption line profile of 121.5 nm Lyman-{alpha} H radiation emitted within the first {approx}1.0 mm of plasma near the anode tip, a peak dissociated H atom concentration of 5.6 Multiplication-Sign 10{sup 17} cm{sup -3} was observed {approx}100 ns into spark formation, with an estimated electron density of 2.65 Multiplication-Sign 10{sup 18} cm{sup -3} determined from Stark broadening. Similarly, simultaneous line fitting of the N 120.0/124.3 nm emission profiles revealed a peak dissociated N atom concentration of 3.8 Multiplication-Sign 10{sup 17} cm{sup -3} during the same discharge period.

• OSTI ID: 22162901
• Journal Information: Applied Physics Letters, Vol. 102, Issue 18; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
74 ATOMIC AND MOLECULAR PHYSICS
ABUNDANCE
ATMOSPHERIC PRESSURE
ATOMS
CONCENTRATION RATIO
DIAGNOSTIC TECHNIQUES
DISSOCIATION
ELECTRON DENSITY
ELECTRON TEMPERATURE
EMISSION
FAR ULTRAVIOLET RADIATION
HYDROGEN
ION TEMPERATURE
MIXTURES
MOLECULES
NITROGEN
PLASMA DENSITY
PLASMA PRODUCTION
SELF-ABSORPTION
SPECTROSCOPY