An ion implanter having a source, a workpiece support and a transport system for delivering ions from the source to an ion implantation chamber that contains the workpiece support. The ion source has an arc chamber for ionizing a source material routed into the arc chamber that defines an exit aperture for routing ions to the transport system and including an arc chamber flange attached to the arc chamber and including a first surface that defines a gas inlet which accepts gas from a source and a gas outlet which opens into the arc chamber. An arc chamber support includes a support flange having a conforming surface that sealingly engages the first surface of arc chamber flange at a region of the gas inlet and further includes a throughpassage that aligns with the gas inlet. A gas supply line routes gas from a gas source through the throughpassage of the support flange and into the gas inlet of said arc chamber flange.