Pulsed Discharge Plasmas in Supercritical Carbon Dioxide

In recent years, several studies about electrical discharge plasma in supercritical carbon dioxide (CO₂) have been carried out. One of the unique characteristics of supercritical fluid is a large density fluctuation near the critical point that can result in marked dramatic changes of thermal conductivity. Therefore, the electrical discharge plasma produced in supercritical fluid has unique features and reactions unlike those of normal plasma produced in gas phase. In our experiments, two types of large volume plasma, namely the pulsed streamer discharge and the pulsed arc discharge have been generated in a supercritical CO₂. It was found that the characteristic of the pulsed discharge plasma in supercritical CO₂ depends on the change of the CO₂ density near the critical region.