This apparatus and method facilitate the synthesis of a single-wall carbon nanotube array. The apparatus includes a reactor, a local heating device, a gaseous carbon supplier, and a reactant gas supplier. The reactor is configured for receiving a catalyst in a reaction zone thereof. The local heating device is configured for selectively heating the reaction zone and/or the catalyst received thereat. The gaseous carbon supplier is configured for introducing gaseous carbon into the reactor from an upstream position of the reaction zone. The reactant gas supplier is configured for introducing a reactant gas containing a carbon source gas into the reactor. A densely aligned, single-wall carbon nanotube array can be achieved due to the proximity to the catalyst of the heating device and due to the gaseous carbon supplier.