The RF plasma source is a truly UHV compatible source. Fully bakeable, with an all-welded stainless steel vacuum envelope and outstanding cooling from a water-jacket which surrounds the hot zone, it is suitable for use in vacuum levels ranging from HV to those found in the most demanding MBE applications. The source can be operated in two distinct modes: The atom source mode is intended principally for low energy and low damage surface treatment and sample growth. A specially designed aperture inhibits the release of ions from the plasma while allowing neutral atoms and molecules to effuse out. In the downstream plasma mode the optics allows ions and higher energy plasma particles to flood out into the chamber. This mode is ideal for growth and cleaning of oxides.