Cleaning of large metallic vessels for plasma confinement devices

The high cleaning efficiency which can be achieved using intense sources of low-energy H(0) and H(+) is demonstrated. The flux densities of the atomic species can be varied in an ultrahigh vacuum apparatus between the time-averaged level in present-day confinement devices and about 5 times that expected in a reactor (H(0) production rate up to approximately 1 g per hour, vessel area about 10 to the 4th power/sq cm). The cleaning rates are high. The mechanisms involved are discussed and agree with observations.