Sub-nanosecond delays of light emitted by streamer in atmospheric pressure air: Analysis of N2( C3Πu) and N2+(B2Σ u +) emissions and fundamental streamer structure

0443590 - ÚFP 2016 RIV US eng J - Journal Article
Hoder, T. - Bonaventura, Z. - Bourdon, A. - Šimek, Milan
Sub-nanosecond delays of light emitted by streamer in atmospheric pressure air: Analysis of N2( C3Πu) and N2+(B2Σ u +) emissions and fundamental streamer structure.
Journal of Applied Physics. Roč. 117, č. 7 (2015), 073302-073302. ISSN 0021-8979. E-ISSN 1089-7550
R&D Projects: GA ČR(CZ) GAP205/12/1709
Institutional support: RVO:61389021
Keywords : streamer * optical diagnostics * nitrogen * emission
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 2.101, year: 2015
http://scitation.aip.org/content/aip/journal/jap/117/7/10.1063/1.4913215

Theoretical analysis of ultra-short phenomena occurring during the positive streamer propagation in atmospheric pressure air is presented. Motivated by experimental results obtained with tens-of-picoseconds and tens-of-microns precision, it is shown that when the streamer head passes a spatial coordinate, emission maxima from N2 and N2+ radiative states follow with different delays. These different delays are caused by differences in the dynamics of populating the radiative states, due to different excitation and quenching rates. Associating the position of the streamer head with the maximum value of the self-enhanced electric field, a delay of 160 ps was experimentally found for the peak emission of the first negative system of N2+. A delay dilatation was observed experimentally on early-stage streamers and the general mechanism of this phenomenon is clarified theoretically. In the case of the second positive system of N2, the delay can reach as much as 400 ps.
Permanent Link: http://hdl.handle.net/11104/0246277