scholarly journals Effect of External Magnetic Field on Long DC Arc Characteristics with Rng-shaped Anode

2021 ◽  
Vol 333 ◽  
pp. 03004
Author(s):  
Akio Hashizawa ◽  
Manabu Tanaka ◽  
Takayuki Watanabe ◽  
Tomohiro Koga
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
High Speed ◽  
Plasma Jet ◽  
Jet Flow ◽  
Critical Issue ◽  
Fluctuation Phenomena ◽  
High Speed Camera ◽  
Electrode Gap ◽  
Dc Arc

Fluctuation phenomena of plasma jet flow in an innovative long DC arc system with a ring-shaped anode were successfully clarified by a high-speed camera visualization. The long DC arc with long electrode gap distance more than 350 mm has been applied to gas decomposition due to its advantages of long plasma length, resulting in long residence time of treated gas. However, large heat loss at a conventional hemispherical-shaped anode was a critical issue in the long DC arc system. Therefore, the ring-shaped anode was utilized to convert large energy loss at the anode into the plasma jet flow. High-speed camera observation revealed the effect of external magnetic field on the fluctuation phenomena. Plasma jet fluctuates with the frequency of several tens Hz when the magnetic field was applied. These understanding of arc and plasma jet fluctuation enables to improve the capability of long DC arc system.

An Investigation of Close-Electrode Intensification in a dc Arc in a Magnetic Field

1970 ◽  
Vol 24 (1) ◽  
pp. 95-98 ◽  
Author(s):  
A. Petrakiev ◽  
R. Milanova
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Cathode Region ◽  
Spectral Lines ◽  
Anode Region ◽  
Temperature Range ◽  
Dc Arc

An investigation of the distribution of the intensity of spectral lines in the gap length of a copper dc arc of 7A, burning both with and without nonhomogenous magnetic field, will be described in this paper. The close-electrode intensification effect of spectral lines has been observed and its variation with the time of preliminary burning and the gap length has been investigated. It has been established that close-electrode intensification appears only with the ionic lines. An increase of the intensity of some spectral lines and certain variations in their distribution have been observed when the arc is burning in a magnetic field. The temperature range has been studied in its relationship to the gap length. The temperature around the cathode region is approximately 6500 K and that around the anode region is about 6000 K. The superposition of an external magnetic field contributes to an increase of the temperature of about 400 K. Some possibilities for the application of these effects in the case of spectral analytical determinations have been suggested.

scholarly journals Investigation of the Arc Characteristics of Switching DC Arcs on Hydrogen Containing Gas Mixtures

2019 ◽  
Vol 6 (1) ◽  
pp. 69-72 ◽  
Author(s):  
D. Gonzalez ◽  
S. Gortschakow ◽  
S. Yu ◽  
F. Werner
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
High Speed ◽  
Gas Mixtures ◽  
High Speed Imaging ◽  
Arc Characteristics ◽  
Pressure Discharge ◽  
Model Chamber ◽  
Imaging And Spectroscopy ◽  
Dc Current

<p>The characteristics of switching DC current arcs in  hydrogen  containing gas mixtures under pressure were investigated using a model chamber. The switching device consists of an electro-mechanic double breaker unit with copper contacts. High-speed imaging and spectroscopy were used to observe and to characterize the switching arc. The experiments indicate how the dynamic interaction of an external magnetic field with a high-pressure discharge causes an elongation and twisting of the arc-channel and consequently a voltage increase. Comparative measurements with and without external magnetic field indicate a strong influence of this factor. Cu and N lines together with strongly broadened H lines were observed.</p>

Synthesizing Cubic Diamond Crystal Using DC Plasma Jet CVD

2019 ◽  
Vol 825 ◽  
pp. 71-76
Author(s):  
Hiromichi Toyota ◽  
Xia Zhu ◽  
Ryoya Shiraishi ◽  
Kazuto Nakajima ◽  
Yukiharu Iwamoto ◽  
...  
Keyword(s):  
High Speed ◽  
Catalytic Effect ◽  
Plasma Jet ◽  
Methanol Solution ◽  
Arc Plasma ◽  
Plasma Power ◽  
Experimental Conditions ◽  
Diamond Crystals ◽  
Dc Arc ◽  
Solution Gas

Diamond crystals are successfully synthesized by irradiating DC arc plasma jet to the substrate set in a methanol solution. It is the important procedure to preheat the substrate by inert Ar plasma jet before introducing the methanol solution gas to the plasma jet gun. The effects of two experimental conditions, the incident power and the substrates, are investigated. In the case of the Si substrate, cubic crystalline diamond grains of same size are synthesized at the plasma power of 470W. High speed hetero epitaxy is expected by using this method. In the case of the tungsten carbide substrate, diamond crystals and carbon nanotubes are simultaneously synthesized at the plasma power of 260W. The catalytic effect of Co binder in the substrate may cause the chemical reaction of the nanotube synthesis.

scholarly journals Investigation of the Arc-Anode Attachment Area by Utilizing a High-Speed Camera

2016 ◽  
Vol 3 (1) ◽  
pp. 1-4 ◽  
Author(s):  
P. Ondac ◽  
A. Maslani ◽  
M. Hrabovsky
Keyword(s):  
Flow Structure ◽  
Power Distribution ◽  
High Speed ◽  
Average Velocity ◽  
Anode Voltage ◽  
Plasma Jet ◽  
High Speed Camera ◽  
Plasma Arc ◽  
Hydrodynamic Waves ◽  
Dc Plasma

The arc-anode attachment in the DC plasma arc influences power distribution in the plasma, a lifespan of anode and flow structure of plasma jet. A movement of the attachment and the surrounding plasma was directly observed by using a high-speed camera (max. 1,080,000 fps). The observations were compared with cathode-anode voltage measurements (sample rate 80 MHz). We have directly measured the average velocity of the attachments and hydrodynamic waves above them, as well as the characteristic dwell times and dwell frequencies of the attachments.

scholarly journals Stability, spatial extension and extinction of an electric arc in aeronautical conditions of pressure under 540 V DC

2019 ◽  
Vol 87 (3) ◽  
pp. 30901
Author(s):  
Romaric Landfried ◽  
Mohamed Boukhlifa ◽  
Thierry Leblanc ◽  
Philippe Teste ◽  
Jonathan Andrea
Keyword(s):  
High Speed ◽  
Electric Arc ◽  
High Speed Camera ◽  
Arc Length ◽  
Electrode Gap ◽  
Arc Current ◽  
The Mean ◽  
The Stability ◽  
Energy Dissipated

This work deals with the characterization of DC electric arcs in aeronautical conditions of pressure (from 104 Pa to 105 Pa). Observations have been made with the help of a high speed camera and various characteristics of electric arc under 540 V DC have been studied: the stability arc length, the extinction gap, the arc duration and the mean energy dissipated in the arc. The arc current intensity range is 10–100 A. The obtained results show that the arc stability length, extinction electrode gap, arc duration and energy dissipation in the arc have a direct correlation with the pressure and the current in the circuit.

Effect of External Magnetic Field on the Volatilization of Elements in the dc Arc

1978 ◽  
Vol 32 (3) ◽  
pp. 272-275 ◽  
Author(s):  
A. A. Fakhry ◽  
M. A. Eid ◽  
M. S. Hashem
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Spectral Line ◽  
Spectral Lines ◽  
Line Intensities ◽  
Carbon Arc ◽  
Dc Arc ◽  
The Magnetic Field ◽  
Silicate Sample

In the present investigation opposing magnetic fields are applied to the free burning carbon arc with a silicate sample (granodiorite) in its anode crater. The magnetic field promoted the selective volatilization of the elements present in the sample. As a result, a depression in the spectral line intensities of Mn, Ti, Th, and Fe as well as the background was observed. At the same time the intensity of the spectral lines of Ag, Ge, Pb, In, and Cu is enhanced. The latter elements are of great significance since they are used as pathfinders for gold.

Vibration Characteristics of Magnetic Fluid Droplet Adsorbed to Magnetized Needlepoint in Alternating Magnetic Field

2012 ◽  
Vol 721 ◽  
pp. 108-113
Author(s):  
Sota Inomata ◽  
Seiichi Sudo ◽  
Hidemasa Takana ◽  
Hideya Nishiyama
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fluid ◽  
High Speed ◽  
Video Camera ◽  
Alternating Magnetic Field ◽  
Camera System ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Video Camera System

The dynamic behavior of a magnetic fluid droplet adsorbed to magnetized needlepoint in alternating magnetic field was studied with a high speed video camera system. The directions of alternating magnetic field were parallel and opposite to static magnetic field of magnetized needlepoint. It was found that the surface of magnetic fluid droplet responds to the external magnetic field in elongation and contraction. The frequency of magnetic fluid droplet oscillation was exactly same of the external magnetic field. The shape and instability oscillations of the magnetic fluid droplet were revealed experimentally.

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