A cylindrical-post magnetron sputtering source is described in which the paths of the magnetic confinement tunnel and entrapped electron drift circuit extend along the cylindrical axis. Then (and only then) can the associated sputtering discharge be scanned circumferentially over the target by rotating the generating magnet within the cylindrical cathode. The design of a basic magnet for this purpose is given which can have any desired length of extension and consequent uniform target erosion and sputter emission of coating material from a cylindrical cathode. From the variations in discharge voltage and deposition rate with applied current for a cylindrical magnetron operating with such a rotating magnet, it is concluded that the trapping of secondary electrons is nearly complete and the energy efficiency of sputtering emission corresponds closely to the theoretical limit. Measurements of the magnetic field, deposition rate, probe potential, heating flux and film stresses as functions of the angle around a stationary (non-rotating) magnet reveal that the emission of coating material, electrons and energetic particles from such a source is markedly directional, although these effects are time averaged by rotation during normal operation. Finally, an advanced spiral discharge is shown, which incorporates the same basic principle of axial extension of the magnetic tunnel and electron drift circuit but accomplishes spatial as well as time averaging of the sputtered flux to a given substrate.