A plasma reactor includes a chamber body having an interior space that provides a plasma chamber, a gas distributor, a pump coupled to the plasma chamber, a workpiece support to hold a workpiece, an intra-chamber electrode assembly comprising a plurality of filaments extending laterally through the plasma chamber, each filament including a conductor surrounded by a cylindrical insulating shell, the plurality of filaments including a first multiplicity of filaments and a second multiplicity of filaments arranged in an alternating pattern with the first multiplicity of filaments, a first bus coupled to the first multiplicity of filaments and a second bus coupled to the second multiplicity of filaments, an RF power source to apply RF signal the intra-chamber electrode assembly, and at least one RF switch configured to controllably electrically couple and decouple the first bus from one of i) ground, ii) the RF power source, or iii) the second bus.