Abstract: A moveable ion source is provided in apparatus for ion implantation to enable ions to be directed from different directions onto bulky target objects. The ion source may be connected on the outside of a vacuum chamber or on a mobile arm within it.The ion source is supplied with both gas and electricity via a single cable. The supply cable has a multi-layered structure with gas flow being supported through a relatively thin inner tube which also carries the h.t. transmission and return conductors. A relatively thick tube is provided around the inner tube to insulate the transmission and return conductors from an earth conductor and to provide mechanical strength. A special coupling is used to interconnect the supply cable with the ion source housing.