- here is the relevant source:
United States Patent Application 20010001654 Kind Code A1 YUDASAKA, MASAKO ; et al. May 24, 2001
PROCESS FOR PRODUCING SINGLE-WALL CARBON NANOTUBES UNIFORM IN DIAMETER AND LASER ABLATION APPARATUS USED THEREIN
AbstractSingle-wall carbon nanotubes are produced from carbon vapor in the presence of nickel-cobalt catalyst vapor, and the carbon vapor and the nickel-cobalt catalyst vapor are constantly generated from a carbon pellet and a nickel-cobalt pellet under radiation of YAG laser beams so that the single-wall carbon nanotubes are constant in diameter.