A process for producing carbon nanotubes includes carbon plasma generation with microwave energy, plasma stabilization, and product deposition. Stabilization homogenizes the plasma energy density and concentration, leading to a more efficient reactor. A transition metal catalyst and associated catalyst support are used to form the end product. The formation region may have variations of geometry and supporting equipment that will affect the rate and purity of production. The formation region is immediately downstream from the plasma stabilization region such that the apparatus may be mounted on a robotic arm for direct deposition of product.