Thermal inequilibrium of atmospheric helium microwave plasma produced by an axial injection torch

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2121931· OSTI ID:20719652

Alvarez, R; Rodero, A; Quintero, M C; Sola, A; Gamero, A; Ortega, D ^[1]

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1. Department of Physics, University of Cordoba, Rabanales Campus, Albert Einstein Building, E-14071 Cordoba (Spain)

The population density of several excited states has been obtained spectroscopically in a helium plasma sustained by a torch device at atmospheric pressure as a function of the radius in the plasma for different conditions of microwave power and plasma gas flow. The ground-state atom density is determined from the gas temperature, which is deduced from the rotational temperature of the molecular nitrogen ions. The population distribution is fitted to the theoretical results of a collisional-radiative model that includes particle transport. A large deviation of the measured populations is found from the theoretical populations for local thermodynamic equilibrium. The plasma at any radial position is far from local thermodynamic equilibrium; the equilibrium deviation parameter of the ground state is larger than 10 000. The equilibrium deviation parameters of the measured excited-state populations obey the theoretical p{sub k}{sup -6} exponential law.

• OSTI ID: 20719652
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 98; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERIC PRESSURE
ELECTRON TEMPERATURE
EXCITED STATES
GAS FLOW
GROUND STATES
HELIUM
ION TEMPERATURE
LTE
MICROWAVE RADIATION
NITROGEN IONS
PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA PRESSURE
POPULATION DENSITY
THERMODYNAMICS