A. Bourdon et P. Vervisch, 3-BODY RECOMBINATION RATE OF ATOMIC NITROGEN IN LOW-PRESSURE PLASMA FLOWS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 54(2), 1996, pp. 1888-1898
A nonlinear collisional-radiative model for atomic nitrogen has been d
eveloped in order to determine effective recombination and associated
ionization coefficients for either optically thin or optically thick p
lasmas where 10(18) m(-3)less than or equal to n(e) less than or equal
to 10(21) m(-3) and 2000 K less than or equal to T-e less than or equ
al to 12 000 K. A time-dependent approach confirms the importance of t
he quasi-steady-state condition to derive meaningful rate coefficients
. In order to implement these coefficients in plasma flow codes, simpl
e analytical expressions are proposed. Significant discrepancies with
existing literature values are pointed out and discussed. In recombini
ng conditions, the relaxation time necessary to reach the quasi-steady
-state is calculated, and depends on the electron number density and o
n the electron temperature. This time limits the validity of the recom
bination coefficient, especially in optically thick cases. Finally, fo
r practical applications, the number of levels in Saha-Boltzmann equil
ibrium at the quasisteady-state is also examined.