Absorption of laser radiation in an optical discharge plasma in a gas mixture stream

1991 ◽  
Vol 24 (7) ◽  
pp. 1086-1087 ◽  
Author(s):  
B G Giren
1985 ◽  
Vol 15 (9) ◽  
pp. 1221-1227
Author(s):  
E V Dan'shchikov ◽  
V A Dymshakov ◽  
F V Lebedev ◽  
A V Ryazanov

1985 ◽  
Vol 15 (12) ◽  
pp. 1633-1635 ◽  
Author(s):  
A F Glova ◽  
V F Lebedev ◽  
V P Yartsev

2022 ◽  
Vol 92 (2) ◽  
pp. 209
Author(s):  
В.Н. Зудов ◽  
А.В. Тупикин

The influence of an electric field on the plasma of an optical discharge in subsonic and supersonic air flows has been studied experimentally. The presence of a weak electric field practically does not affect the size of the plasma formation, but, regardless of the configuration of the field lines and the polarity of the applied voltage, it leads to a decrease in the probability of optical breakdown. The experiment has shown that the plasma created by focused laser radiation is very sensitive to the presence of an electric field. When a voltage exceeding 22 kV was applied to the ring electrodes, powerful quasi-stationary streamers were formed in the flow. The presence of an optical discharge plasma made it possible to create an electric discharge in fields with an intensity below the breakdown threshold of the medium. The effect of quenching and the processes of development of an optical discharge were studied depending on the speed and characteristics of the electric field. Quenching of the optical discharge was observed when a voltage of 22 kV and higher was applied. Despite the preservation of the geometric dimensions of the optical discharge, the high-temperature region in the flow can be increased by using electric streamers. This leads to an increase in the energy supplied to the flow, and thus allows combustion to be initiated and flame stabilized at higher flow rates. Key words: experimental modeling, laser radiation, optical breakdown, electric field, electric discharge, sub- and supersonic air flow.


2021 ◽  
Vol 63 (12) ◽  
pp. 2070-2075
Author(s):  
Hongda Li ◽  
Y. N. Panchenko ◽  
M. V. Andreev ◽  
A. V. Puchikin ◽  
S. A. Yampolskaya ◽  
...  

10.14311/1123 ◽  
2009 ◽  
Vol 49 (2) ◽  
Author(s):  
M. Nevrkla

A device producing Z-pinching plasma as a source of XUV radiation is described. Here a ceramic capacitor bank pulse-charged up to 100 kV is discharged through a pre-ionized gas-filled ceramic tube 3.2 mm in diameter and 21 cm in length. The discharge current has amplitude of 20 kA and a rise-time of 65 ns. The apparatus will serve as experimental device for studying of capillary discharge plasma, for testing X-ray optics elements and for investigating the interaction of water-window radiation with biological samples. After optimization it will be able to produce 46.9 nm laser radiation with collision pumped Ne-like argon ions active medium. 


2020 ◽  
Vol 843 ◽  
pp. 159-164
Author(s):  
Yukihiro Kusano ◽  
Daan Jonas Hottentot Cederløf ◽  
Søren Fæster

Bundles or fabrics of sized glass fibres were treated by a dielectric barrier discharge plasma in a He/CF4 gas mixture at atmospheric pressure with and without ultrasonic irradiation. The plasma treatment introduced fluorine both inside and outside of the fibre bundle, decreasing wetting of glycerol. Ultrasonic irradiation markedly increased the fluorine content as well as the silicon, calcium, and aluminium contents, indicating simultaneous fluorination and preferential etching of organic components. It is indicated that plasma treatment in a He/CF4 gas mixture can be used for controlling the surface properties of glass fibre bundles, and that ultrasonic irradiation can enhance functionalization and etching.


2019 ◽  
Vol 19 (5) ◽  
pp. 391-398
Author(s):  
E. A. Gusachenko ◽  
M. N. Lyulyukin ◽  
D. V. Kozlov

The influence of negatively polar plasma of crown discharge on the rate of photocatalytic oxidation (PCO) of vapors of acetone and benzene was investigated by studying dynamics of changes in the composition of gas-air mixture in a 404 L reactor using in-situ IR spectroscopy. Titanium (Hombifine N) was used as the photocatalyst; it was lighted with a UV-lamp at the wavelength λ = 365 nm. The rate of the photocatalytic oxidation of the substrate vapor was compared to the oxidation rate in crown discharge plasma, to the rate of dark oxidation with ozone (side product of the discharge burning), to the rate of photocatalytic oxidation in the presence of ozone, as well as to the rate of the photocatalytic oxidation under medium treatment with the crown discharge plasma. The rate of oxidation of various substrates was shown to be much lower in individual plasma and in ozone-containing atmosphere than in photocatalytic oxidation but application of the crown discharge led to an increase in the rate of photocatalytic oxidation and in the rate of oxidation in ozone-containing atmosphere. Under the action of the discharge, ozone was not accumulated in considerable proportion in the gas mixture but after consumption of 80–90 % of the oxidized substrate. The order of acetone PCO with respect to ozone was determined. It was shown that the action of plasma allowed benzene PCO to be noticeably accelerated due to considerable depression of the photocatalyst deactivation compared to that during individual PCO of benzene.


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