Results are presented that have been obtained while operating the graphite hollow cathode duoplasmatron ion source in dual mode under constant discharge current. This dual mode operation enabled us to obtain the mass and emission spectra simultaneously. In mass spectra C-3 is the main feature but C-4 and C-5 are also prominent, whereas in emission spectra C-2 is also there and its presence shows that it is in an excited state rather than in an ionic state. These facts provide evidence that C-3 is produced due to the regeneration of a soot forming sequence and leave it in ionic state. C-3 is a stable molecule and the only dominant species among the carbon clusters that survives in a regenerative sooting environment at high-pressure discharges.
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