Plasma confinement ring assemblies are provided that include confinement rings adapted to reach sufficiently high temperatures on plasma-exposed surfaces of the rings to avoid polymer deposition on those surfaces. The plasma confinement rings include thermal chokes adapted to localize heating at selected portions of the rings that include the plasma exposed surfaces. The thermal chokes reduce heat conduction from those portions to other portions of the rings, which causes selected portions of the rings to reach desired temperatures during plasma processing.