  A hollow cathode source with a specially designed cusp magnetic field B whose
z component is a function of radius and the azimuth angle, provides clustering
environment to the sputtered carbon atoms and ions. The distinctive features of
the source are its sooting properties that depend upon the two well-defined
regions within the discharge. The cusp field drives both of these regions but
in different modes. One region ionizes the source gas, introduces the sputtered
carbon from the graphite hollow cathode while the other is the collision
dominated gyration motion of the positive carbon ions along the z component of
the magnetic field contours. Tunability of plasma discharge characteristics
provides the tool to investigate clustering in the sooting plasma
