Am. Diamy et al., Measurements by optical and mass spectrometry of the density of active species in the flowing afterglow of a N-2/(10(-4)-10(-3))CH4 plasma, SURF COAT, 112(1-3), 1999, pp. 38-42
The influence of small quantities of methane on the behaviour of the active
species N, N-2(A) and N-2(+) (B) has been studied by emission and mass spe
ctrometry. The nitrogen atom concentration [N] is in the (0.1-4) x 10(15) p
articles cm(-3) range under the emission and mass spectrometry. The nitroge
n atom concentration [N] is in the (0.1-4)x 1015 particles cm(-3) range und
er the experimental conditions investigated. For a N-2-0.01%CH4 mixture, [N
] is twice as high as for pure N-2. The metastable N-2(A) concentration is
approximately 10(11) particles cm(-3), i.e it varies from 3 to 6 times lowe
r than in pure N, as the pressure decreases from 25 to 12.5 mbar, and the e
xcited ion density [N-2(+)(B)], is 5 x 10(4)-2 x 10(6) particles cm(-3), i.
e. 100-1000 times lower than in pure N-2. (C) 1999 Elsevier Science S.A. Al
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