On the spatio-temporal patterns formation in low-temperature plasmas

Experimental results concerning the formation of spatial and spatio-temporal patterns in low-temperature discharge plasmas are presented. These structures appear as single or multiple luminous structures attached to the anode surface, or electrode-free in the case of radio-frequency or microwave plasmas. Probe measurements revealed that a double layer exists at the edge of each structure, controlling the particle and energy exchange with the surrounding plasma. In dynamic state, the double layer periodically disrupts and re-aggregates, so that a spatio-temporal structure emerges. The role of elementary processes, such as the electron-neutral impact excitations and ionizations, is analyzed.