Fullerene study from vaporization of graphite in a thermal plasma jet

The overall objective of this work was to develop diagnostic techniques that could be applied to a fullerene synthesis system. A helium plasma was generated by a 20 kW DC plasma torch and channeled through a graphite tunnel to approximate the thermal plasma tailflame fullerene synthesis environment encountered in the tetrachlorethylene system. Two diagnostic techniques were studied to characterize the temperature and electron density of the plasma. The first method uses the radiation spectrum of the C2 molecule to estimate a heavy species temperature in the plasma. The second method uses the Stark broadening of atomic helium lines to calculate electron densities.It was found that the heavy species temperature in the plasma at the outlet of the tunnel was approximately 5000 K. Both these diagnostic methods are expected to be easily applicable to future thermal plasma fullerene synthesis systems and provide valuable information on the local conditions. (Abstract shortened by UMI.