A hollow cathode source with a specially designed cusp magnetic field Bz (r,θ) provides clustering environment to thesputtered carbon atoms and ions. Source's distinctive features are itssooting properties that depend upon the two well-defined regions within thedischarge. The cusp field drives both of these regions but in differentmodes – one region ionizes the source gas, introduces the sputtered C fromthe hollow cathode while the other is the collision dominated gyrationalmotion of the C+ ions along Bz (r,θ) contours.Tunability of plasma's discharge characteristics provides the tool toinvestigate clustering in the sooting plasma.