Thermal plasma diagnostic method based on the ratio of plasmaradiation emitted in various spectral regions

摘要

A new diagnostic method to evaluate the thermal plasma temperature is investigated for argon and80%Ar-20%H2 plasmas at atmospheric pressure. Its principle is to use the different evolutionsaccording to the temperature of the emitted plasma radiation in various spectral regions. Thistechnique needs a preliminary study to calculate this evolution and we will present the bases ofthis calculation. An experimental study is developed to validate the method. The setup iscomposed of a wall-stabilised arc and a multichannel spectrometer. Some usual diagnosticmethods are applied to calculate the temperature on the axis of the cylindrical plasma. Theseresults are compared with the new technique. We limit to work on the spectral regions between300 nm and 1100 nm where self-absorption is often negligible. First experimental results arepresented and discussed for an argon plasma.