combustion reaction within the combustion chamber according to one embodiment at high temperatures the thermal insulation layer becomes electrically conductive a portion of the thermal insulation layer can be used as an electrode for further controlling characteristics of the combustion reaction within the combustion chamber thus in one embodiment the process 500 comprises applying ground voltage or a third voltage to the portion of the thermal insulation layer used as an electrode the voltage can be applied to thermal insulation layer by passing a conductor through an aperture in the conductive outer layer and the electrical insulation layer to the thermal insulation layer in one embodiment the process 500 includes cooling the outer conductive layer of the wall of the combustion chamber by passing water along the outside of the conductive layer of the combustion chamber wall in this case a water jacket configuration contains the water as it is passed along the outer conductive layer of the wall of the combustion chamber the water jacket is thermally coupled to the outer conductive layer of the combustion chamber wall such that the water cools the outer conductive layer of the combustion chamber wall similarly the water jacket may act as at least a portion of a thermal load that is heated by the combustion reaction in one embodiment a conductor is positioned adjacent a bottom portion of the combustion chamber therefore in one embodiment the process 500 includes applying a voltage to the conductor near the bottom of the combustion chamber in this case the conductor near the bottom of the combustion chamber.