Soft X-ray radiation due to a nanosecond diffuse discharge in atmospheric-pressure air

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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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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Microstructure of the current channel of an atmospheric-pressure diffuse discharge in a rod-plane air gap

Technical Physics ◽

10.1134/s1063784207010094 ◽

2007 ◽

Vol 52 (1) ◽

pp. 52-58 ◽

Cited By ~ 19

Author(s):

A. G. Rep’ev ◽

P. B. Repin ◽

V. S. Pokrovskiĭ

Keyword(s):

Atmospheric Pressure ◽

Air Gap ◽

Current Channel ◽

Diffuse Discharge

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Nitriding of yttria-stabilized zirconia in atmospheric pressure microwave plasma

Journal of Materials Research ◽

10.1557/jmr.2009.0245 ◽

2009 ◽

Vol 24 (6) ◽

pp. 2021-2028 ◽

Cited By ~ 4

Author(s):

R. Milani ◽

R.P. Cardoso ◽

T. Belmonte ◽

C.A. Figueroa ◽

C.A. Perottoni ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Atmospheric Pressure ◽

Microwave Plasma ◽

Plasma Nitriding ◽

Nitrided Layer ◽

Zirconium Nitride ◽

Stabilized Zirconia ◽

Partially Stabilized Zirconia ◽

X Ray ◽

Yttria Partially Stabilized Zirconia

High temperature plasma nitriding of yttria-partially-stabilized zirconia in atmospheric pressure microwave plasma was investigated. The morphological, mechanical, and physicochemical characteristics of the resulting nitrided layer were characterized by different methods, such as optical and scanning electron microscopy, microindentation, x-ray diffraction, narrow resonant nuclear reaction profiling, secondary neutral mass spectrometry, and x-ray photoelectron spectroscopy, aiming at investigating the applicability of this highly efficient process for nitriding of ceramics. The structure of the plasma nitrided layer was found to be complex, composed of tetragonal and cubic zirconia, as well as zirconium nitride and oxynitride. The growth rate of the nitrided layer, 4 µm/min, is much higher than that obtained by any other previous nitriding process, whereas a typical 50% increase in Vickers hardness over that of yttria-partially-stabilized zirconia was observed.

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OMCVD of thin films from metal diketonates and triphenylbismuth

Journal of Materials Research ◽

10.1557/jmr.1990.1169 ◽

1990 ◽

Vol 5 (6) ◽

pp. 1169-1175 ◽

Cited By ~ 40

Author(s):

A. D. Berry ◽

R. T. Holm ◽

M. Fatemi ◽

D. K. Gaskill

Keyword(s):

Electron Microscopy ◽

Vapor Deposition ◽

Atmospheric Pressure ◽

Electron Spectroscopy ◽

Auger Electron ◽

Chemical Vapor ◽

X Ray Diffraction ◽

Strontium Barium ◽

X Ray ◽

Scanning Electron

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.

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Epitaxial Growth of Magnesia Films on Single Crystalline Magnesia Substrates by Atmospheric-Pressure Chemical Vapor Deposition

Journal of Materials Science Research ◽

10.5539/jmsr.v5n2p56 ◽

2016 ◽

Vol 5 (2) ◽

pp. 56

Author(s):

Keiji Komatsu ◽

Pineda Marulanda David Alonso ◽

Nozomi Kobayashi ◽

Ikumi Toda ◽

Shigeo Ohshio ◽

...

Keyword(s):

Chemical Vapor Deposition ◽

Single Crystal ◽

Vapor Deposition ◽

Atmospheric Pressure ◽

Reciprocal Lattice ◽

Chemical Vapor ◽

X Ray ◽

Pole Figures ◽

Out Of Plane ◽

Pressure Chemical

<p class="1Body">MgO films were epitaxially grown on single crystal MgO substrates by atmospheric-pressure chemical vapor deposition (CVD). Reciprocal lattice mappings and X-ray reflection pole figures were used to evaluate the crystal quality of the synthesized films and their epitaxial relation to their respective substrates. The X-ray diffraction profiles indicated that the substrates were oriented out-of-plane during MgO crystal growth. Subsequent pole figure measurements showed how all the MgO films retained the substrate in-plane orientations by expressing the same pole arrangements. The reciprocal lattice mappings indicated that the whisker film showed a relatively strong streak while the continuous film showed a weak one. Hence, highly crystalline epitaxial MgO thin films were synthesized on single crystal MgO substrates by atmospheric-pressure CVD.</p>

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Preparation of InN by Means of AP-HCVD Using In Buffer Layers

MRS Proceedings ◽

10.1557/proc-1040-q09-32 ◽

2007 ◽

Vol 1040 ◽

Author(s):

Hiroaki Yokoo ◽

Naoki Wakiya ◽

Naonori Sakamoto ◽

Takato Nakamura ◽

Hisao Suzuki

Keyword(s):

Electrical Property ◽

Surface Morphology ◽

Buffer Layer ◽

Atmospheric Pressure ◽

Indium Nitride ◽

Buffer Layers ◽

Crystal Quality ◽

X Ray Diffraction ◽

X Ray ◽

Quality Surface

AbstractWe have grown indium nitride (InN) films using In buffer layer on an a-plane sapphire substrate under atmospheric pressure by halide CVD (AP-HCVD). Growth was carried out by two steps: deposition In buffer layer at 900 °C and subsequent growth of InN layer at 650 °C. In order to compare, we also grown InN films on an a-plane sapphire. The InN films are investigated on crystal quality, surface morphology and electrical property using high-resolution X-ray diffraction (HR-XRD), X-ray pole figure, scanning electron microscope (SEM), Hall measurement. The results show that the crystal quality, surface morphology and electrical property of InN films are improved by using In buffer layer.

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Chemical Vapor Deposition of Strontium-Barium-Niobate

MRS Proceedings ◽

10.1557/proc-243-457 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 6

Author(s):

A. Greenwald ◽

M. Horenstein ◽

M. Ruane ◽

W. Clouser ◽

J. Foresi

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Atmospheric Pressure ◽

Chemical Vapor ◽

X Ray Diffraction ◽

Strontium Barium Niobate ◽

Electrical And Optical Properties ◽

Strontium Barium ◽

X Ray ◽

Boston University

AbstractSpire Corporation has deposited strontium-barium-niobate by chemical vapor deposition at atmospheric pressure using Ba(TMHD), Sr(TMHD), and Nb ethoxide. Deposition temperature as 550°C in an isothermal furnace. Films were deposited upon silicon (precoated with silica), platinum, sapphire, and quartz. Materials were characterized by RBS, X-ray diffraction, EDS, electron, and optical microscopy. Electrical and optical properties were measured at Boston University.

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