Simple experimental and analytical methods to estimate the power coupling efficiency in plasma discharges

A simple experimental method to estimate the power effectively absorbed by a plasma is presented. It relies on a thermal management study that is applied to the whole discharge system, providing the energy released by the plasma and lost by convection and radiation at the reactor walls. The methodology is illustrated in the case of H-2 Electron Cyclotron Resonance microwave plasma. Nevertheless, this method can be extended to a variety of electrical discharge or feed gases. Using this method, an experimental coupling efficiency of similar to 22 +/-similar to 8% was derived. In comparison, an analytical balance of the plasma power absorption yields a theoretical coupling efficiency of similar to 28 +/-similar to 9%.