Atmospheric pressure discharges

In our lab we developed several plasma jet sources. The electrodes of the plasma jet are made of copper foil, copper wire and ITO foil and as a working gas usually we use helium. We also developed double and multi plasma jet suitable for the treatment of larger area. Optical emission spectroscopy of the atmospheric plasma jets is one of the standard diagnostic technique for obtaining the space-time development. bulletFor time resolved imaging precise synchronization of iCCD camera and plasma powering signal is very important because we use short exposures (several nano seconds). From the images it can be seen that plasma is not continues and it is consisted of fast moving streamers (bullets). The measured speed of the bullets are typically 15 km/s that is much larger than the gas velocity. Double plasma jet behavior is similar like the single jet, only observed difference is the asynchronous appearance of the bullet. Plasma effluent is not continuous, but is made of pulsed atmospheric pressure streamers (PAPS) or “plasma bullets”. The mechanism of the creation of the plasma bullet is associated with the propagation of the ionization front of a streamer, but it still requires further studies and better understanding. In order to do this we are performing time-resolved mass spectrometry synchronized with ICCD camera.