Speaker
Antonio D'Angola
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.4004.pdf
EquilTheTA: a web-access tool for LTE plasma thermodynamics and
transport properties
A. D’Angola1,2 , A. Laricchiuta1 , G. Colonna1
1 PLASMI Lab NANOTEC CNR Bari (Italy)
2 Scuola di Ingegneria, Università della Basilicata Potenza (Italy)
EquilTheTA is a web-access tool to calculate thermodynamic and transport properties of
complex plasmas in local thermodynamic equilibrium (LTE) in a wide pressure and tempera-
ture range. Thermodynamic properties are calculated starting from the atomic and molecular
internal partition functions, which are, in turn, evaluated from internal levels of the species.
For atoms and atomic ions, the electronic energy levels are available in open databases and are
extended by recurring to the Ritz-Rydberg approach to ensure completeness for each internal
configuration. Equilibrium composi- 100
SiO SiO2
10–10 SiO+ SiC+
tions are calculated by using a hier-
10–20 SiC
archical algorithm which solves one 10–30 CO
reaction at a time [1, 2] avoiding 10–10 CO2
molar fractions
CO2
10–20
the solution of large non-linear sys- CO +
CO+
2
10–30
C
tems of equations. For these reasons, 10–10 C3
C2
the method is fast and accurate and 10–20 C2
C+
2
10–30
always converges. Recently, an auto-
10–10
matic determination of the optimal re- 10–20 O2
O3
action scheme has been implemented 10–30 2
10 103 104 105
temperature (K)
to speedup the convergence. Transport Figure 1: Molar fractions of SiC + O2 .
properties are calculated by using high order Chapman-Enskog expansion. The transport cross
section database is populated by an hybrid phenomenological/multi-potential approach, ensur-
ing accurate description of binary interactions and widening the capability of the tool. The code
is accessed through a friendly interface which includes the possibility of creating a plasma mix-
ture starting from the species and to set the thermodynamic conditions (pressure or density,
temperature). As an example, Figure 1 shows molar fractions of molecules and atomic negative
ions obtained in the case of a plasma of technological interest such as SiC+O2 [3].
References
[1] W. R. Smith, R. Missen, Can. J. Chem. Eng. 66 (4) (1988) 591–598.
[2] G. Colonna, A. D’Angola, Comp. Phys. Comm. 163 (2004) 177–190.
[3] G. Colonna et al., Plasma Sources Science and Technology 27(1) (2018) 015007.
