Speaker
Description
Non-equilibrium atmospheric pressure plasmas received a lot of attentions in the last decade due to promising applications in the biomedical field and for material processing [1]. Reactive species generated by plasmas, such as hydroxyl are considered to play essentials roles for these applications. Atomic hydrogen, another dominant species, shows great potentials in ion reduction leading to nanoparticle synthesis [2].
In this study, we study the H production in a cold atmospheric pressure plasma jet driven by a nanosecond pulser while flowing helium and H2O mixture. The one dimensional two-photon absorption laser induced fluorescence signal of atomic hydrogen (H-TALIF) is recorded along the axis of symmetry of a plasma jet by aligning the laser beam into the quartz tube of the jet. The absolute density calibration is achieved by performing Kr-TALIF without discharge in situ.
In this report, the H atom transportation, generation and decay are investigated and particularly the impact of plasma generation and modulating frequencies. The high densities inside the tube, lead to a fast recombination of the H density before it reaches the jet effluent. The results also show memory effects for repetition frequencies in excess of 2 kHz. Combined with information of coupling energy and emission intensity, we will use the spatial and temporal variation of the atomic H density to discuss the main production and destruction pathways.
Acknowledgement: This work is supported by the US Department of Energy through the Plasma Science Centre (DE-SC0001939) and Office of Fusion Energy Sciences (DE-SC0016053).
- X. Lu. G.V. Naidis, M. Laroussi, S. Reuter, D. Graves and K. Ostrikov, 2016, Phys. Rep. 630 pp1-84
- S. Kondeti, U. Gangal, S. Yatom and P. Bruggeman, 2017, J. Vac. Sci. Technol. A 35 061302.
