ON-LINE TEMPERATURE MEASUREMENT IN A PLASMA REACTOR FOR FULLERENE SYNTHESIS

Vaporization of carbon particles injected in a plasma flow is an alternative to existing processes for mass production of fullerenes. In order to obtain a large fullerene-soot production the residence time of particle at temperature larger than the vaporization temperature must be large enough. This critical point was checked in the pilot reactor by OES.
The helium plasma was generated inside a carbon nozzle by a 3-phase AC plasma source using graphite electrodes. The plasma flow was then cooled in a graphite cylinder. Plasma temperature was measured using H_β line and C₂ Swan band in the upper part of the nozzle and at the entrance of the cylinder respectively. The results show that inside this volume, the plasma temperature is larger than or equal to 4500K and is very sensitive to the arc current.