We have modified the conventional arc-discharge method for the production of single-walled carbon nanotubes (SWNTs) by using a bowl-shaped cathode that can direct the are plasma in a specified direction and using a combination of cobalt, nickel, iron and cerium as an efficient catalyst, with sulfur as a promoter and tin as a nanowelding element. Under optimized conditions, SWNT super bundles can be efficiently produced with carbon-to-tube yields of over 70%.