Faculty of Physics, “Alexandru Ioan Cuza” University, 11 Carol I Blvd., RO-700506 Iasi, Romania

Fireballs are well-known luminous complex space charges structures obtained in front of positively biased electrodes immersed in plasma, up to a critical value of the applied voltage. In dynamic state, the double layer existing at the border of the fireball periodically disrupts and re-aggregates, releasing bunches of charged particles (electrons and positive ions) in the surrounding plasma and perturbing all the plasma parameters.

Here we report on the experimental investigation of the interaction between two fireballs obtained on two different positively biased electrodes. The dynamic states of the fireballs was recorded when different parameters were modified (distance between the electrodes, gas pressure, plasma density, voltages on the electrodes). Maximum values of the fireball dynamics frequency were observed for certain values of the distance between the electrodes, as well as for certain values of the voltages applied on the electrodes. The dynamics of the two fireballs remain synchronized in all experimental conditions.