Diagnostics of heat exchange of a chemically inert nonequilibrium plasma with surfaces

A method of differential scanning calorimetry in a gas discharge is developed. The method is meant for measuring the contributions of various heat exchange mechanisms to the integral heat flux from a nonequilibrium plasma onto a surface. Methods for experimental determination of typical features of different mechanisms are discussed. As an example, indications of an additional heat flux with a density of 38 +/- 4 mW/cm(2) from a high-frequency oxygen discharge plasma at a pressure of 50 Pa on a silicon surface, which was modified by a 2-nm-thick Langmuir-Blodgett film, are determined. The method allows for reliable discrimination between the detected heat flux and fluxes of different origin (e.g., a flux produced by gas heat conduction).