Nonuniqueness of two-temperature Guldberg-Waage and Saha equations: Influence on thermophysical properties of SF{sub 6} plasmas

Journal Article · Fri Nov 15 00:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4829035· OSTI ID:22218457

Wang, Weizong ^[1]; Rong, Mingzhe ^[2]; Spencer, Joseph W. ^[3]

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1. Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094 (China)
2. State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)
3. Department of Electrical Engineering and Electronics, The University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom)

This paper focuses to study how the choice of Guldberg-Waage and Saha equations affects the thermodynamic properties and transport coefficients of SF{sub 6} plasmas under both thermal equilibrium and non-equilibrium conditions. The species composition is numerically determined using two typical forms of two-temperature Saha equations and Guldberg-Waage equations that have appeared in the literature. The great influence of the choice of the excitation temperature on the plasma composition and hence the thermodynamic properties and transport coefficients is discussed as well. Transport coefficients are calculated with most recent collision interaction potentials by adopting Devoto's electron and heavy particle decoupling approach but expanded to the third-order approximation (second-order for viscosity) within the framework of Chapman-Enskog method. Furthermore, an analysis of the effect of different definitions of Debye length on the properties values was performed as well. The results are computed for various values of pressures from 0.10 atm to 10 atm and non-equilibrium parameter, i.e., ratio of the electron temperature to the heavy particle temperature from 1 to 5 with electron temperature range from 300 to 40 000 K. Both forms of Guldberg-Waage and Saha equations used here can give completely the same value when the two-temperature model reaches the special case of local thermodynamic equilibrium. It has been observed that all above mentioned factors can significantly modify the plasma species composition and consequently affect the thermodynamic and transport properties.

• OSTI ID: 22218457
• Journal Information: Physics of Plasmas, Vol. 20, Issue 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
APPROXIMATIONS
CHARGED-PARTICLE TRANSPORT
DEBYE LENGTH
ELECTRON TEMPERATURE
ELECTRONS
EXCITATION
ION TEMPERATURE
LTE
NUMERICAL ANALYSIS
PLASMA
POTENTIALS
SAHA EQUATION
SULFUR FLUORIDES
THERMODYNAMIC PROPERTIES
VISCOSITY