IEC plasma discharge for fullerene production

Summary form only given, as follows. One approach to fullerene production is the a use of a hydrocarbon such as methane in a plasma discharge. The efficiency of this approach is hampered, however, because hydrogen atoms in the discharge can quench the recombination of carbon atoms prior to full C/sub 60/ formation. Inertial electrostatic confinement (IEC) offers a possible solution, however. A potential well structure develops in the center of a spherical IEC discharge such that carbon and hydrogen ions tend to concentrate in different regions of the well, giving a higher conversion to C/sub 60/. Experiments with He-methane mixtures have confirmed the basic principle, but further research is under way to determine optimum conversion efficiencies achievable. In this case the IEC is operated in a pulsed mode so that carbon recombination occurs rapidly as the plasma cools between pulses. Removal of product C/sub 60/ is done through a double valve arrangement at the bottom of the chamber, so that vacuum need not be broken. An alternate approach, also under study, is to operate the IEC in the "jet" mode. Then, the plasma entering the jet is predominately from the outer region of the potential well structure, again providing separation. Preliminary results and calculations for both configurations will be presented.