The cavity ring-down spectroscopy of C-2 in a microwave plasma

The formation of C-2 in an argon/hydrogen/methane 2.45 GHz microwave plasma has been studied by cavity ring-down spectroscopy and optical emission spectroscopy by observing the d 3Pi(g)-a 3Pi(u) optical transition in absorption and emission, respectively. The two states are shown to be in equilibrium under the plasma conditions adopted for this study. The plasma parameters are similar to those adopted for the growth of nanocrystalline diamond. (C) 2002 Elsevier Science B.V. All rights reserved.