Investigation of the microchannel structure in the initial phase of the discharge in air at atmospheric pressure in the “pin (anode)-plane” gap

2020 ◽  
Vol 27 (12) ◽  
pp. 123507
Author(s):  
K. I. Almazova ◽  
A. N. Belonogov ◽  
V. V. Borovkov ◽  
V. S. Kurbanismailov ◽  
Z. R. Khalikova ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Initial Phase ◽  
Anode Plane

scholarly journals Влияние предыонизации на микроканальную структуру искрового разряда в воздухе в промежутке острие-плоскость

2022 ◽  
Vol 92 (1) ◽  
pp. 52
Author(s):  
А.А. Тренькин ◽  
К.И. Алмазова ◽  
А.Н. Белоногов ◽  
В.В. Боровков ◽  
Е.В. Горелов ◽  
...  
Keyword(s):  
Wave Front ◽  
Electron Concentration ◽  
Atmospheric Pressure ◽  
Initial Phase ◽  
Discharge Channel ◽  
Cathode Region ◽  
Ionization Wave ◽  
Anode Region ◽  
Microstructure Formation ◽  
Micron Diameter

The initial phase of a spark discharge in the gap between the pin (cathode) and a plane 1.5 mm long in atmospheric pressure air under conditions of preliminary photoionization by an auxiliary discharge was investigated by the method of shadow photography. In the absence of preionization, the discharge from the first nanoseconds after breakdown is an aggregate of a large number of micron-diameter channels. It was found that the electron concentration resulting from preionization, estimated at 108  109 cm-3, increases the degree of uniformity of the discharge channel in the near-cathode region; however, in the near-anode region, the channel remains microstructured. Within the framework of the mechanism of microstructure formation due to the instability of the ionization wave front, a criterion for the formation of a uniform discharge is obtained and an explanation of the results obtained is presented.

Мicrochannel Structure Parameters in the Initial Phase of a Spark Discharge in a Tip–Plane Gap in Atmospheric-Pressure Air

2021 ◽  
Vol 47 (1) ◽  
pp. 71-74
Author(s):  
K. I. Almazova ◽  
A. A. Amirova ◽  
A. N. Belonogov ◽  
V. V. Borovkov ◽  
G. B. Ragimkhanov ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Initial Phase ◽  
Spark Discharge ◽  
Structure Parameters

scholarly journals Плазменные и газодинамические приэлектродные процессы в начальной фазе микроструктурированного искрового разряда в воздухе

2020 ◽  
Vol 46 (15) ◽  
pp. 10
Author(s):  
К.И. Алмазова ◽  
А.Н. Белоногов ◽  
В.В. Боровков ◽  
В.С. Курбанисмаилов ◽  
Г.Б. Рагимханов ◽  
...  
Keyword(s):  
Experimental Data ◽  
Physical Model ◽  
Electron Concentration ◽  
Atmospheric Pressure ◽  
Initial Phase ◽  
Dynamic Parameters ◽  
Dynamic Effects ◽  
Associated Gas ◽  
Electrode Processes ◽  
Gas Dynamic

The results of studies of the dynamics of near-electrode processes in the initial phase of the spark are presented. discharge in air at atmospheric pressure in the tip – plane geometry. Near the surface of a flat After the breakdown of the cathode, regions with a size of about 50 μm and more were recorded with an increased electron concentration of (3–8)•10^19 cm^(– 3). Based on experimental data on erosion the effect of a discharge on the surface of a flat electrode and the associated gas-dynamic effects a physical model of near-electrode processes is proposed, based on which estimates are made gas dynamic parameters.

A High-Voltage Terminal for a Field-Emission Gun

1972 ◽  
Vol 30 ◽  
pp. 428-429
Author(s):  
N. F. Ziegler
Keyword(s):  
Field Emission ◽  
High Voltage ◽  
Atmospheric Pressure ◽  
Power Supplies ◽  
High Coherence

A high-voltage terminal has been constructed for housing the various power supplies and metering circuits required by the field-emission gun (described elsewhere in these Proceedings) for the high-coherence microscope. The terminal is cylindrical in shape having a diameter of 14 inches and a length of 24 inches. It is completely enclosed by an aluminum housing filled with Freon-12 gas at essentially atmospheric pressure. The potential of the terminal relative to ground is, of course, equal to the accelerating potential of the microscope, which in the present case, is 150 kilovolts maximum.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

Some changes during the initial phase of the unit system in a large mental hospital

1966 ◽  
Author(s):  
Robert P. Barrell ◽  
Alan S. DeWolfe ◽  
Fred E. Spaner
Keyword(s):  
Initial Phase ◽  
Mental Hospital ◽  
Unit System

Modeling of mass-transportation of tris-(acetylacetonato)chromium(III) at atmospheric pressure

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-251-Pr8-258 ◽  
Author(s):  
N. E. Fedotova ◽  
A. N. Mikheev ◽  
N. V. Gelfond ◽  
I. K. Igumenov ◽  
N. B. Morozova ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Mass Transportation

Modeling of silicon epitaxial growth with SiHCl3 in a CVD barrel reactor at atmospheric pressure

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-221-Pr8-228
Author(s):  
E. de Paola ◽  
P. Duverneuil ◽  
A. Langlais ◽  
M. Nguyen
Keyword(s):  
Epitaxial Growth ◽  
Atmospheric Pressure ◽  
Barrel Reactor
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