High voltage isolation and cooling for an inductively coupled plasma ion source

A plasma source comprising:

• a reactor chamber within which a plasma is generated to produce at least one plasma product for processing or imaging the substrate, as an ion source for proton therapy, as ion thrusters, or in high energy particle accelerators, the reactor chamber including outer walls that are all actively biased to a high voltage;
• a gas source coupled to the reactor chamber to provide gas into the reaction chamber;
• an exit aperture coupled to the reactor chamber to allow extraction of ions from the reactor chamber;
• a first source of radio frequency power;
• a plurality of induction coils adjacent to the reactor chamber and coupled to said first source of radio frequency power to inductively couple power into the plasma from said first source of radio frequency power;
• a coolant fluid circuit defined within the plasma source in contact with the induction coils and reactor chamber;
• and
• a source of dielectric fluid in fluid communication with the coolant circuit wherein both the reactor chamber and induction coils are electrically isolated from each other and from ground and cooled by the dielectric fluid.