|
This article is cited in 21 scientific papers (total in 21 papers)
Extreme light fields and their applications
Production of extended plasma channels in atmospheric air by amplitude-modulated UV radiation of GARPUN-MTW Ti : sapphire — KrF laser. Part 2. Accumulation of plasma electrons and electric discharge control
V. D. Zvorykin, A. A. Ionin, A. O. Levchenko, G. A. Mesyats, L. V. Seleznev, D. V. Sinitsyn, I. V. Smetanin, E. S. Sunchugasheva, N. N. Ustinovskii, A. V. Shutov P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow
Abstract:
The problem of the production of extended (~1 m) plasma channels is studied in atmospheric air by amplitude-modulated laser pulses of UV radiation, which are a superposition of a subpicosecond USP train amplified in a regenerative KrF amplifier with an unstable confocal resonator and a quasi-stationary lasing pulse. The USPs possess a high (0.2 — 0.3 TW) peak power and efficiently ionise oxygen molecules due to multiphoton ionisation, and the quasi-stationary lasing pulse, which has a relatively long duration (~100 ns), maintains the electron density at a level ne = (3 — 5) × 1014 cm — 3 by suppressing electron attachment to oxygen. Experiments in laser triggering of high-voltage electric discharges suggest that the use of combined pulses results in a significant lowering of the breakdown threshold and enables controlling the discharge trajectory with a higher efficiency in comparison with smooth pulses. It was shown that controlled breakdowns may develop with a delay of tens of microseconds relative to the laser pulse, which is many orders of magnitude greater than the lifetime of free electrons in the laser-induced plasma. We propose a mechanism for this breakdown, which involves speeding-up of the avalanche ionisation of the air by negative molecular oxygen ions with a low electron binding energy (~0.5 eV) and a long lifetime (~1 ms), which are produced upon cessation of the laser pulse.
Keywords:
high-voltage discharge, discharge guiding, laser discharge triggering, plasma channels in the atmosphere, air ionisation by laser radiation.
Received: 30.01.2013 Revised: 12.02.2013
Citation:
V. D. Zvorykin, A. A. Ionin, A. O. Levchenko, G. A. Mesyats, L. V. Seleznev, D. V. Sinitsyn, I. V. Smetanin, E. S. Sunchugasheva, N. N. Ustinovskii, A. V. Shutov, “Production of extended plasma channels in atmospheric air by amplitude-modulated UV radiation of GARPUN-MTW Ti : sapphire — KrF laser. Part 2. Accumulation of plasma electrons and electric discharge control”, Kvantovaya Elektronika, 43:4 (2013), 339–346 [Quantum Electron., 43:4 (2013), 339–346]
Linking options:
https://www.mathnet.ru/eng/qe13559 https://www.mathnet.ru/eng/qe/v43/i4/p339
|
|