Abstract: Apparatus and method for plasma synthesis of carbon nanotubes couple a plasma nozzle to a reaction tube/chamber. A process gas comprising a carbon-containing species is supplied to the plasma nozzle. Radio frequency radiation is supplied to the process gas within the plasma nozzle, so as to sustain a plasma within the nozzle in use, and thereby cause cracking of the carbon-containing species. The plasma nozzle is arranged such that an afterglow of the plasma extends into the reaction tube/chamber. The cracked carbon-containing species also pass into the reaction tube/chamber. The cracked carbon-containing species recombine within the afterglow, so as to form carbon nanotubes in the presence of a catalyst.