Results are presented of density and temperature measurements made within a large volume magnetically confined plasma which could be applicable to a plasma neutralizer. rf power at a few megahertz is inductively coupled into an argon plasma by means of a multi‐turn insulated antenna within the plasma chamber. This large volume, dense plasma offers potential advantages over an equivalent plasma created by dc ion source technology, since as no filaments are required for normal operation, possible contamination from filament material is not a problem and more importantly the device requires virtually no maintenance as the need to replace filaments is eliminated.