TABLE I:

Chemical and plasma processes included in model and their associated rate coefficients.

Number	Reaction	Rate Coefficient, k =	Units	Reference
Atomic Recombination
R1	2 N + N2 → N2(B) + N2	$8.27\times {10}^{-34}\exp \left(\frac{500}{T_{\text{g}}}\right)$	cm6 s−1	20–27
Fluorescent
R2	N2(A) → N2 + hν	0.5	s−1	28 and 29
R3	N2(B) → N2(A) + hν	1.52 × 10−5	s−1	23 and 30
R4	N2(C) → N2(A) + hν	2.69 × 10−7	s−1	30 and 31
Energy Pooling
R5abc	2N2(A) → N2(B) + N2(v) + ϵtr	$2.9\times {10}^{-9}\sqrt{\frac{T_{\text{g}}}{300}}$	cm3 s−1	32–35
R6bcd	2 N2(A) → N2(C) + N2(v)	$2.6\times {10}^{-10}\sqrt{\frac{T_g}{300}}$	cm3 s−1	29 and 35
Electron-Ion Recombination & Ionization
R7a	${\text{e}}^{-}+{\text{N}}_4^{+}\to {\text{N}}_2(\text{A})+{\text{N}}_2$	$2.5\%\times 2.4\times {10}^{-6}\sqrt{\frac{300}{T_e}}$	cm3 s−1	34, 36, and 37
R8a	${\text{e}}^{-}+{\text{N}}_4^{+}\to {\text{N}}_2(\text{B})+{\text{N}}_2$	$87\%\times 2.4\times {10}^{-6}\sqrt{\frac{300}{T_{\text{e}}}}$	cm3 s−1	34, 36–38
R9a	${\text{e}}^{-}+{\text{N}}_4^{+}\to {\text{N}}_2(\text{C})+{\text{N}}_2$	$11\%\times 2.4\times {10}^{-6}\sqrt{\frac{300}{T_{\text{e}}}}$	cm3 s−1	34, 36, 37, and 39
R10	$2{\text{e}}^{-}+{\text{N}}_4^{+}\to {\text{e}}^{-}+2{\text{N}}_2$	$7\times {10}^{-20}{\left(\frac{300}{T_e}\right)}^{4.5}$	cm6 s−1	34
R11	${\text{e}}^{-}+{\text{N}}_3^{+}\to \text{N}+{\text{N}}_2$	$2.0\times {10}^{-7}\sqrt{\frac{300}{T_{\text{e}}}}$	cm3 s−1	23 and 37
R12b	${\text{e}}^{-}+{\text{N}}_2^{+}\to 2\text{N}+{ϵ}_{\text{tr}}$	$2.8\times {10}^{-7}\sqrt{\frac{300}{T_{\text{e}}}}$	cm3 s−1	23 and 40
R13	${\text{e}}^{-}+{\text{N}}_2^{+}\to {\text{N}}_2+h\nu$	$4\times {10}^{-12}{\left(\frac{300}{T_{\text{e}}}\right)}^{0.7}$	cm3 s−1	41
R14	${\text{e}}^{-}+{\text{N}}_2^{+}+{\text{N}}_2\to 2{\text{N}}_2$	$6\times {10}^{-27}{\left(\frac{300}{T_{\text{e}}}\right)}^{1.5}$	cm6 s−1	23
R15	$2{\text{e}}^{-}+{\text{N}}_2^{+}\to {\text{e}}^{-}+{\text{N}}_2$	$1\times {10}^{-19}{\left(\frac{300}{T_{\text{e}}}\right)}^{4.5}$	cm6 s−1	23
R16	${\text{e}}^{-}+{\text{N}}_2\to 2{\text{e}}^{-}+{\text{N}}_2^{+}$	$5.05\times {10}^{-11}\frac{\sqrt{T_{\text{e}}}+1.10\times {10}^{-5}{T}_{\text{e}}^{1.5}}{\exp \left(\frac{1.82\times {10}^5}{T_{\text{e}}}\right)}$	cm3 s−1	42 and 43
R17	${\text{e}}^{-}+{\text{N}}^{+}\to \text{N}+h\nu$	$3.5\times {10}^{-12}{\left(\frac{300}{T_{\text{e}}}\right)}^{0.7}$	cm3 s−1	41
R18	${\text{e}}^{-}+{\text{N}}^{+}+{\text{N}}_2\to \text{N}+{\text{N}}_2$	$6\times {10}^{-27}{\left(\frac{300}{T_{\text{e}}}\right)}^{1.5}$	cm6 s−1	23
R19	$2{\text{e}}^{-}+{\text{N}}^{+}\to {\text{e}}^{-}+\text{N}$	$1\times {10}^{-19}{\left(\frac{300}{T_e}\right)}^{4.5}$	cm6 s−1	23
Quenching
R20	${\text{N}}_3^{+}+{\text{N}}_2(\text{A})\to {\text{N}}^{+}+2{\text{N}}_2$	6 × 10−10	cm3 s−1	44 and 45
R21	${\text{N}}_2^{+}+{\text{N}}_2(\text{A})\to {\text{N}}_3^{+}+\text{N}$	3 × 10−10	cm3 s−1	23, 44, and 46
R22	${\text{N}}_2^{+}+{\text{N}}_2(\text{A})\to {\text{N}}^{+}+\text{N}+{\text{N}}_2$	4 × 10−10	cm3 s−1	17, 44, and 46
R23a	N2(A) + N2 → 2N2	2.0 × 10−17	cm3 s−1	21, 36, 41, 47–50
R24a	N + N2(A) → N + N2	$6.2\times {10}^{-11}{\left(\frac{300}{T_{\text{g}}}\right)}^{2/3}$	cm3 s−1	34, 36, 41, 47, 51–53
R25ab	N2(B) + N2 → N2(A) + N2(v)	$1.2\times {10}^{-11}$	cm3 s−1	23, 33, 35, 36, 46, 54–57
R26bd	N2(C) + N2 → N2(B) + N2(v)	$1.2\times {10}^{-11}{\left(\frac{300}{T_{\text{g}}}\right)}^{0.33}$	cm3 s−1	35 and 58
Ion Conversion
R27	${\text{N}}_4^{+}+{\text{N}}_2\to {\text{N}}_2^{+}+2{\text{N}}_2$	$2.1\times {10}^{-16}\exp \left(\frac{T_{\text{g}}}{121}\right)$	cm3 s−1	36, 46, 59, and 60
R28	${\text{N}}_4^{+}+\text{N}\to {\text{N}}^{+}+2{\text{N}}_2$	$1\times {10}^{-11}$	cm3 s−1	23 and 46
R29	${\text{N}}_4^{+}+\text{N}\to {\text{N}}_3^{+}+{\text{N}}_2$	1 × 10−9	cm3 s−1	61
R30	${\text{N}}_3^{+}+\text{N}\to {\text{N}}_2^{+}+{\text{N}}_2$	6.6 × 10−11	cm3 s−1	23 and 46
R31	${\text{N}}_3^{+}+{\text{N}}_2\to {\text{N}}^{+}+2{\text{N}}_2$	6 × 10−11	cm3 s−1	44 and 46
R32	${\text{N}}_2^{+}+{\text{N}}_2\to {\text{N}}^{+}+\text{N}+{\text{N}}_2$	1.2 × 10−11	cm3 s−1	44 and 46
R33	${\text{N}}_2^{+}+{\text{N}}_2\to {\text{N}}_3^{+}+\text{N}$	5.5 × 10−12	cm3 s−1	44 and 46
R34	${\text{N}}_2^{+}+\text{N}\to {\text{N}}^{+}+{\text{N}}_2$	$7.2\times {10}^{-13}\exp \left(\frac{300}{T_g}\right)$	cm3 s−1	17 and 46
R35	${\text{N}}_2^{+}+2{\text{N}}_2\to {\text{N}}_4^{+}+{\text{N}}_2$	$6.8\times {10}^{-29}{\left(\frac{300}{T_{\text{g}}}\right)}^{1.64}$	cm6 s−1	60
R36	${\text{N}}_2^{+}+\text{N}+{\text{N}}_2\to {\text{N}}_3^{+}+{\text{N}}_2$	$0.9\times {10}^{-29}\exp \left(\frac{400}{T_{\text{g}}}\right)$	cm6 s−1	23 and 46
R37	${\text{N}}^{+}+{\text{N}}_2\to {\text{N}}_2^{+}+\text{N}$	$1\times {10}^{-13}$	cm3 s−1	44
R38	${\text{N}}^{+}+2{\text{N}}_2\to {\text{N}}_3^{+}+{\text{N}}_2$	$2.0\times {10}^{-29}{\left(\frac{300}{T_{\text{g}}}\right)}^{2.0}$	cm6 s−1	62
R39	${\text{N}}^{+}+\text{N}+{\text{N}}_2\to {\text{N}}_2^{+}+{\text{N}}_2$	$1\times {10}^{-29}\left(\frac{300}{T_g}\right)$	cm6 s−1	41
Electron-Neutral Collisions
R40b	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+2\text{N}+{ϵ}_{\text{tr}}$	$\frac{1.2\times {10}^{25}}{N_{\text{A}}{T}_{\text{e}}^{1.6}}\exp \left(-\frac{113.200}{T_{\text{e}}}\right)$	cm3 s−1	35, 43, 63, and 64
R41	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 8.25\times {10}^{-8}$	cm3 s−1	65–68
R42	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(v)$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 8.45\times {10}^{-9}$	cm3 s−1	66–68
R43e	${\text{e}}^{-}+{\text{N}}_2(v)\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}},T_{\text{v}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K},600\text{K})\approx 2.69\times {10}^{-11}$	cm3 s−1	66–68
R44	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(\text{A},v=0-4)$	$f\left(T_{\text{e }}\right)\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 1.59\times {10}^{-12}$	cm3 s−1	66–68
R45e	${\text{e}}^{-}+{\text{N}}_2(\text{A},v=0-4)\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 2.67\times {10}^{-11}$	cm3 s−1	66–68
R46	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(\text{A},v=5-9)$	$f\left(T_{\text{e}}\right),\text{e.g.},f(\mathrm{11\; 600}\text{K})\approx 5.63\times {10}^{-12}$	cm3 s−1	66–68
R47e	${\text{e}}^{-}+{\text{N}}_2(\text{A},v=5-9)\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 1.80\times {10}^{-10}$	cm3 s−1	66–68
R48	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(\text{B})$	$f\left(T_{\text{e}}\right),\text{e.g.},f(\mathrm{11\; 600}\text{K})\approx 2.35\times {10}^{-11}$	cm3 s−1	66–68
R49e	${\text{e}}^{-}+{\text{N}}_2(\text{B})\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.},f(\mathrm{11\; 600}\text{K})\approx 9.85\times {10}^{-10}$	cm3 s−1	66–68
R50	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(\text{A},v>9)$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 4.06\times {10}^{-12}$	cm3 s−1	66–68
R51e	${\text{e}}^{-}+{\text{N}}_2(\text{A},v>9)\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 4.06\times {10}^{-12}$	cm3 s−1	66–68
R52	${\text{e}}^{-}+{\text{N}}_2\to {\text{e}}^{-}+{\text{N}}_2(\text{C})$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 6.18\times {10}^{-12}$	cm3 s−1	66–68
R53e	${\text{e}}^{-}+{\text{N}}_2(\text{C})\to {\text{e}}^{-}+{\text{N}}_2$	$f\left(T_{\text{e}}\right),\text{e.g.,}f(\mathrm{11\; 600}\text{K})\approx 4.06\times {10}^{-9}$	cm3 s−1	66–68
Vibrational-Translational Relaxation
R54	${\text{N}}_2(v)+{\text{N}}_2\to 2{\text{N}}_2$	$f(T_{\text{g}}),\text{e.g.},f(300\text{K})\approx 3.05\times {10}^{-21}$	cm3 s−1	69 and 70

^aTuned value for rate coefficient. See Table IV.

^bReaction contributes to fast gas heating. See Table III.

^cTemperature dependence derived from assumption that $k\propto \overline{v}\propto \sqrt{T_{\text{g}}}.$

^dRelatively large spread of rate coefficients reported in literature. Listed coefficient taken from cited reference. See Table IV for additional references.

^eSuperelastic rate coefficient calculated from inverse cross sections. See text for details.