Extended plasma channels created by UV laser in air and their application to control electric discharges

Journal Article · Sun Feb 15 04:00:00 EST 2015 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X15010067· OSTI ID:22472450

Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Sinitsyn, D. V.; Smetanin, I. V.; Ustinovskii, N. N.; Shutov, A. V. ^[1]

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1. Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

Results are presented from a series of experimental and theoretical studies on creating weakly ionized extended plasma channels in atmospheric air by 248-nm UV laser radiation and their application to control long high-voltage discharges. The main mechanisms of air ionization by UV laser pulses with durations from 100 fs to 25 ns and intensities in the ranges of 3×10{sup 11}–1.5×10{sup 13} and 3×10{sup 6}–3×10{sup 11} W/cm{sup 2}, respectively, which are below the threshold for optical gas breakdown, as well as the main relaxation processes in plasma with a density of 10{sup 9}–10{sup 17} cm{sup −3}, are considered. It is shown that plasma channels in air can be efficiently created by amplitude-modulated UV pulses consisting of a train of subpicosecond pulses producing primary photoelectrons and a long UV pulse suppressing electron attachment and sustaining the density of free electrons in plasma. Different modes of the generation and amplification of trains of subterawatt subpicosecond pulses and amplitude-modulated UV pulses with an energy of several tens of joules were implemented on the GARPUN-MTW hybrid Ti:sapphire-KrF laser facility. The filamentation of such UV laser beams during their propagation in air over distances of up to 100 m and the parameters of the corresponding plasma channels were studied experimentally and theoretically. Laser initiation of high-voltage electric discharges and control of their trajectories by means of amplitude-modulated UV pulses, as well as the spatiotemporal structure of breakdowns in air gaps with length of up to 80 cm, were studied.

• OSTI ID: 22472450
• Journal Information: Plasma Physics Reports, Journal Name: Plasma Physics Reports Journal Issue: 2 Vol. 41; ISSN PPHREM; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BREAKDOWN
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRON ATTACHMENT
ELECTRON DENSITY
ELECTRONS
IONIZATION
KRYPTON FLUORIDE LASERS
LASER RADIATION
PLASMA
PLASMA DENSITY
RELAXATION
SAPPHIRE