This article describes studies performed on the National Superconducting Cyclotron Laboratory’s Superconducting‐ECR (electron cyclotron resonance) ion source for the production of metallic ion beams. The Room Temperature‐ECR ion source as the workhorse for generating metallic ion beams using a solid feed system will be superceded in the future by the Superconducting‐ECR ion source. A series of tests were carried out with a Langmuir probe introduced axially into the plasma chamber of the Superconducting‐ECR ion source. These tests determined the location and shape of the plasma and its floating potential. The results presented show the effect of source bias and axial magnetic field on the plasma boundary. Some preliminary results for gold sputtering are also included. The use of a solid metal, saturated in deuterium, to produce deuterium beams in the Room Temperature‐ECR ion source has also been studied. ©1996 American Institute of Physics.