Modification of copper surface by runaway electrons preionized diffuse discharges at atmospheric pressure

AbstractRunaway electrons preionized diffuse discharge (REP DD) could generate volume non-thermal plasmas at atmospheric pressure, thus is widely used for surface modification. In this paper, two pulsed generators are used to produce REP DD for modifying copper (Cu) foil in atmospheric air. One generator produces repetitive pulses with a peak voltage of 40 kV and a rise time of 150 ns. The other generator produces single pulse with a peak voltage of 280 kV and a rise time of 0.5 ns. After the treatment, the modification results for including the macro topography, chemical composition and microhardness in different depths of the Cu surface are analyzed. In order to estimate the modification results in different areas of the Cu foil, several points from the center to the edge of the Cu sample are selected. It could be observed that the maximal modification effect usually appears in the area where the density of the diffuse discharge plasma is highest. The experimental results show REP DD treatment could significantly decrease the water contact angle and increase surface energy of the Cu foil. Meanwhile, it could decrease the carbon concentration and increase oxygen concentration in the near-surface layer of the Cu sample, and enhance the microhardness in different depths of the Cu foil.

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X-ray radiation and runaway electron beams generated during discharges in atmospheric-pressure air at rise times of voltage pulse of 500 and 50 ns

Laser and Particle Beams ◽

10.1017/s0263034618000150 ◽

2018 ◽

Vol 36 (2) ◽

pp. 186-194 ◽

Cited By ~ 7

Author(s):

D.A. Sorokin ◽

V.F. Tarasenko ◽

Cheng Zhang ◽

I.D. Kostyrya ◽

Jintao Qiu ◽

...

Keyword(s):

Current Pulse ◽

Breakdown Voltage ◽

High Voltage ◽

Rise Time ◽

Atmospheric Pressure ◽

Voltage Pulse ◽

Runaway Electron ◽

Electron Beams ◽

X Ray ◽

Diffuse Discharge

AbstractThe parameters of X-ray radiation and runaway electron beams (RAEBs) generated at long-pulse discharges in atmospheric-pressure air were investigated. In the experiments, high-voltage pulses with the rise times of 500 and 50 ns were applied to an interelectrode gap. The gap geometry provided non-uniform distribution of the electric field strength. It was founded that at the voltage pulse rise time of 500 ns and the maximum breakdown voltage Um for 1 cm-length gap, a duration [full width at half maximum (FWHM)] of a RAEB current pulse shrinks to 0.1 ns. A decrease in the breakdown voltage under conditions of a diffuse discharge leads to an increase in the FWHM duration of the electron beam current pulse up to several nanoseconds. It was shown that when the rise time of the voltage pulse is of 500 ns and the diffuse discharge occurs in the gap, the FWHM duration of the X-ray radiation pulse can reach ≈100 ns. It was established that at a pulse-periodic diffuse discharge fed by high-voltage pulses with the rise time of 50 ns, an energy of X-ray quanta and their number increase with increasing breakdown voltage. Wherein the parameter Um/pd is saved.

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Influence of the Plasma of Nanosecond Diffuse Discharge in Air at Atmospheric Pressure on the Electrophysical Properties of Epitaxial CdHgTe Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.685.676 ◽

2016 ◽

Vol 685 ◽

pp. 676-679

Author(s):

K.A. Lozovoy ◽

D.V. Grigoryev ◽

V.F. Tarasenko ◽

M.A. Shulepov

Keyword(s):

Atmospheric Pressure ◽

Epitaxial Films ◽

Uniform Electric Field ◽

Physical Parameters ◽

Volume Discharge ◽

Nanosecond Duration ◽

Near Surface ◽

Type Conductivity ◽

Diffuse Discharge ◽

P Type

In this paper the influence of the volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of CdHgTe (MCT) epitaxial films of p-type conductivity is investigated. Measurements of electro-physical parameters of MCT samples after irradiation have shown that a layer exhibiting n-type conductivity is formed in the near-surface area of epitaxial films. After more than 600 pulses of influence parameters and thickness of the resulting n-layer is such that the measured field dependence of Hall coefficient corresponds to the material of n-type conductivity. The obtained results show that application of volume nanosecond discharge in air at atmospheric pressure is promising for the modification of the surface properties of epitaxial films of MCT.

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Synthesis of High Quality Graphene Films by Atmospheric Pressure CVD and their Application in Laser Q-Switching

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.514 ◽

2013 ◽

Vol 747 ◽

pp. 514-517 ◽

Cited By ~ 1

Author(s):

Mei Qi ◽

Yu Ping Zhang ◽

Wei Long Li ◽

Man Jiang ◽

Xin Liang Zheng ◽

...

Keyword(s):

Saturable Absorber ◽

Atmospheric Pressure ◽

Graphene Film ◽

Chemical Vapor ◽

Single Pulse ◽

High Quality ◽

Synthesis Conditions ◽

Graphene Films ◽

Q Switching ◽

Cu Foil

Synthesis of high quality graphene films on Cu foil by atmospheric pressure chemical vapor deposition (APCVD) was studied systematically. Acetylene and Cu foil were chosen as the carbon source and the catalyst (or the support) for the synthesis of graphene, respectively. The effect of several synthesized parameters on the structure of graphene films were investigated in detail. The controlled synthesis of graphene and the optimal synthesis conditions were derived. The prepared graphene film was transferred to a coated mirror as a Q-switching saturable absorber used in a Nd:YAG laser. The obtained shortest laser pulse width with single-pulse energy of 8.18 μJ was 242.8 ns. The results indicate that graphene film synthesized by APCVD can be excellently used as saturable absorber material in ultrashort pulse laser.

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ELECTRON YIELD DETECTORS FOR NEAR SURFACE EXAFS AT ATMOSPHERIC PRESSURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1986829 ◽

1986 ◽

Vol 47 (C8) ◽

pp. C8-159-C8-162 ◽

Cited By ~ 1

Author(s):

K. I. PANDYA ◽

K. YANG ◽

R. W. HOFFMAN ◽

W. E. O'GRADY ◽

D. E. SAYERS

Keyword(s):

Atmospheric Pressure ◽

Near Surface ◽

Electron Yield

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Generation of Runaway Electrons and X-ray at a Microsecond Voltage Rise Time in Different Gases

2020 7th International Congress on Energy Fluxes and Radiation Effects (EFRE) ◽

10.1109/efre47760.2020.9242071 ◽

2020 ◽

Author(s):

Alexander Burachenko ◽

Victor Tarasenko ◽

Evgenii Baksht

Keyword(s):

Rise Time ◽

Runaway Electrons ◽

Voltage Rise ◽

X Ray ◽

Different Gases

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Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

Scientific Reports ◽

10.1038/s41598-021-88553-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andrzej Sikora ◽

Dariusz Czylkowski ◽

Bartosz Hrycak ◽

Magdalena Moczała-Dusanowska ◽

Marcin Łapiński ◽

...

Keyword(s):

Contact Angle ◽

Surface Modification ◽

Chemical Composition ◽

Water Contact Angle ◽

Plasma Sheet ◽

Atmospheric Pressure ◽

Argon Plasma ◽

Fullerene Derivative ◽

Water Contact ◽

Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

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Observations of X-rays from Laboratory Sparks in Air at Atmospheric Pressure under Negative Switching Impulse Voltages

Atmosphere ◽

10.3390/atmos10040169 ◽

2019 ◽

Vol 10 (4) ◽

pp. 169 ◽

Cited By ~ 1

Author(s):

Mahbubur Rahman ◽

Pasan Hettiarachchi ◽

Vernon Cooray ◽

Joseph Dwyer ◽

Vladimir Rakov ◽

...

Keyword(s):

Rise Time ◽

Atmospheric Pressure ◽

Opposite Polarity ◽

X Rays ◽

X Ray ◽

Impulse Voltage ◽

First Time ◽

Switching Impulses ◽

Low Rate

We present observations of X-rays from laboratory sparks created in the air at atmospheric pressure by applying an impulse voltage with long (250 µs) rise-time. X-ray production in 35 and 46 cm gaps for three different electrode configurations was studied. The results demonstrate, for the first time, the production of X-rays in gaps subjected to switching impulses. The low rate of rise of the voltage in switching impulses does not significantly reduce the production of X-rays. Additionally, the timing of the X-ray occurrence suggests the possibility that the mechanism of X-ray production by sparks is related to the collision of streamers of opposite polarity.

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