Electrical measurements in the positive column of a D.C. glow discharge in oxygen.

by Howard Warren Rundle in [Toronto]

Written in English
Published: Pages: 55 Downloads: 246
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Subjects:

  • Electric discharges through gases,
  • Oxygen

Edition Notes

ContributionsToronto, Ont. University.
Classifications
LC ClassificationsLE3 T525 MA 1965 R85
The Physical Object
Pagination55 leaves.
Number of Pages55
ID Numbers
Open LibraryOL14746159M

an electric discharge could be used in an anemometer application. Encouraged by Dr. Theodor Von Karman, the glow had been investigated to measure the flow mass-flux as an anemometer. Lindvall used the D.C. (direct current) glow discharge to measure the velocity of the turbulent flow behind a cylinder based on the correlation of circuit voltage. A low-pressure, electrical discharge transverse to a strong magnetic field is characterized by large-amplitude, plasma fluctuations (1). 2 These spontaneous electrical fluctuations are hundreds of volts in amplitude, and play an important role in the scattering, diffusion, and ionizing processes of the gas (2). Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. is not at all important for a glow discharge. It is merely a side effect." Your reference says "A neon display lamp uses the positive column for its light". @article{osti_, title = {A probe for electrical conductivity measurements in ionized gases}, author = {Hill, Lemmuel L. and Marshall, Theodore. and Crapo, Benjamin. J.}, abstractNote = {A probe technique for measuring the electrical conductivity in a small region of an ionized flow field is described. The technique involves observing the interaction between an ionized gas and a small.

A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow.A fluorescent lamp converts electrical energy into useful light much more efficiently. plasma generation and measurement. NRP discharges are produced by short-duration 10 ns high-voltage 5–10 kV positive-polarity pulses at pulse repetition frequencies f of 1–30 kHz across a discharge gap –10 mm formed by two steel electrodes in a vertical pin-pin configuration. The NRP discharges are created in preheated – K at-.   The method of claim 2 which further comprises the step of operating the radio frequency the uniform glow discharge plasma having an electric field of from 1 to 12 kV/cm. 8. The method of claim 2 which further comprises the step of producing an electric field for trapping ions in the electric field without trapping electrons in the electric. An electric current is the rate of flow of electric charge past a point: 2: or region.: An electric current is said to exist when there is a net flow of electric charge through a region.: In electric circuits this charge is often carried by electrons moving through a can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas ().SI unit: ampere.

Definition. Plasma is a state of matter in which an ionized gaseous substance becomes highly electrically conductive to the point that long-range electric and magnetic fields dominate the behaviour of the matter. The plasma state can be contrasted with the other states: solid, liquid, and gas.. Plasma is an electrically neutral medium of unbound positive and negative particles (i.e. the. In an arc light, the light is concentrated at the electrode. As the power of an arc light is increased its color changes from yellow-white to white to blue-white. The sharp discontinuities in the nature of the light from an electric discharge as it switches from a red glow to a . D.A. Erwin, J.A. Kunc and M.A. Gundersen, “Determination of Electric Field and Electron Temperature in the Positive Column of a High-Power Hydrogen Thyratron from Non-Intrusive Measurements”, Applied Physics Lett (). sputtering. A Grimm-style glow discharge excitation source, whose hollow anode had an inner diameter of 8 mm, was employed as the excitation source. Mujawar () deal with the study of oxygen negative ion formation in the anodic glow plasma. The anodic glow is characterized by a double layer having a steep gradient in Te and electron density.

Electrical measurements in the positive column of a D.C. glow discharge in oxygen. by Howard Warren Rundle Download PDF EPUB FB2

Previously reported measurements of electron energy distribution and ion concentrations in the positive column of an oxygen discharge are used as a basis for discussing the ion equilibrium. The degree of dissociation is shown to be of order 10% and reasons are advanced for the view that negative ions O - are destroyed in the gas phase by.

This set of measurements is presented for the positive column of a glow discharge created in a cm-diameter Pyrex tube, for a pressure between and 5 Torr and a d.c.

current up to 80 mA. Experimental study of a d.c. oxygen glow discharge by V.U.V. absorption spectroscopy | Cited by: In our contribution, the positive column of oxygen DC glow discharge is investigated using methods of computational physics at medium pressures (– Pa) and discharge currents from 20 to 40 mA.

In this paper we report the measurements we performed of the reduced electric field strength E/p in the positive column in the range of the gas pressure and tube radius product of Cited by: 3.

A glow discharge is a kind of plasma consisting of equal concentration of positive and negative charges and a large number of neutral species. The dc-glow discharge plasmas have been used for plasma applications in the low and intermediate pressure regions in modern technology.

The dissociation of hydrogen molecules in the positive column of a DC glow discharge in an H2-Ar mixture Article in High Temperature 46(2) April with 5 Reads How we measure 'reads'.

On the Anomaly of the Electrical Field Strength in the Magnetized Positive Column of Glow Discharges at Small Currents Beiträge aus der Plasmaphysik, Vol. 23, No.

4 Probe Measurements in a Beam Plasma DischargeCited by:   Introduction. Glow Discharge Mass Spectrometry (GDMS) is one of the most powerful solid state analytical methods for the direct determination of traces, impurities and depth profiling of solids.

1–5 Glow discharge mass spectrometers, which are commercially available with fast and sensitive electrical ion detection, allow direct trace elemental determination in solid materials with. An atmospheric dc glow discharge using a liquid cathode and an axial miniature helium flow was generated stably between a nozzle anode and an electrolyte cathode (NaCl solution) in ambient air.

Under low-current operation, the typical structure of dc glow discharges, i.e. a negative glow, a Faraday dark space and positive column, was observed. In the traditional DC normal glow discharge in a still argon at atmospheric pressure, the contraction of the positive column, which is attributed to the recombination process, allows the gas Cited by: Spectroscopic Study of Argon DC Glow Discharge Abdou A.

Garamoon, Ahmed Samir, Farouk Fahmy Elakshar, A. Nosair, and Eizaldeen F. Kotp Abstract—In this paper, emission spectra of both positive column (PC) and negative glow (NG) regions of the dc glow (DSO) (type HM) was used to measure the I–V curve of the discharge. The voltage. Electric discharge machining is a method of machining in which, as shown in Figure 1, when an electrode and a workpiece are brought closer to each other with pulse voltage being applied between them, dielectric breakdown occurring at a certain distance between them triggers discharge, whose high temperature and pressure in turn cause part of the workpiece to be melted and blown.

The gas temperature in the positive column is higher than the gas temperature in the electrode regions. Similar variation of was observed by Rayleigh scattering in a similar discharge with a maximum of K in the positive column, K at the water cathode and K at the metal anode respectively. The gas temperature by Rayleigh scattering Cited by: A glow discharge is a plasma formed by the passage of electric current through a gas.

It is often created by applying a voltage between two electrodes in a glass tube containing a low-pressure gas. When the voltage exceeds a value called the striking voltage, the gas ionization becomes self-sustaining, and the tube glows with a colored light.

The color depends on the gas used. The positive column differs significantly between arcs operated at low pressures (say, below 10 cmHg pressure) and arcs at higher pressures, such as atmospheric. At low pressures, it is like the positive column of a glow discharge, with a very high electron temperature (40,K is not unusual) and a low ion and gas temperature (say, K).

The post-discharge of an RF plasma torch supplied with helium and oxygen gases is characterized by mass spectrometry, optical emission spectroscopy and electrical measurements. We have proved the existence of a dc current in the post-discharge (1–20μA), attributed to the Penning ionization of atmospheric nitrogen and.

How to create DC glow discharge. In DC glow discharge, there is a fixed cathode and a fixed anode. Electrons will be accelerated from cathode to anode and acquire more energy. Along the way to the anode, electrons will experience many collisions with other ions and neutrals.

Upon increasing the discharge current, the normal glow discharge becomes abnormal (Figure 3) and a contraction of the positive column ensues.

The column separates from the walls of the vessel, and there begins within the column an additional process, known as volume recombination, which contributes to the loss of charged particles.

What causes the 'Faraday Dark Space' between the positive column and the negative glow in a discharge tube. As I understand it there is a glow at the negative cathode end of the tube and at the anode end of the tube too, but there is a gap in the middle (Which I think is known as the Faraday's Dark Space), and I can't find any reason why.

The positive and negative polarity discharge current pulse forms were examined between steel cylinder-Al 2 O 3 plane electrodes in helium glow and pseudoglow discharges under atmospheric pressure at 10 kHz. The theoretically determined current pulses agreed very closely in form and magnitude with those recorded by: To measure the plasma parameters such as the elec-tron temperature, the plasma density, and the electron energy distribution function, which are produced by the virtual cathode DC glow discharge, a single elec-tric probe is used [15,16].

In Fig. 4 the electric probe. When I was doing the experiment of glow discharge, I lowered the voltage between electrodes and find that the length of positive column will increased quickly around a certain voltage(the interval of change is less than 3 volts), and I do not know why.

The gas used is air, the pressure is around 50Pa, the distance between electrodes is about 10cm. Based on the idea of increasing the number of initial electrons by changing the structures of the cathode, a method of generating the glow discharge plasma in the DC electric field by using the three-potential electrode structure is proposed.

When the cathode takes the form of a spiral-contact electrode, a coupled electrode structure is by: 2. Electrical & Photometric Measurement of High Intensity Discharge Lamps [Not Available] on *FREE* shipping on qualifying : Not Available. @article{osti_, title = {On the stability of a dc-driven oxygen discharge in cylindrical geometry}, author = {Bruhn, B and Richter, A and May, B}, abstractNote = {Starting from the hydrodynamic equations describing the positive column of glow discharges in oxygen, the stability of the homogeneous state is investigated.

The model contains electrons, positive and negative ions as. The magnetic field effect on the current-voltage characteristic curves of glow discharge in argon at low pressures has been experimentally investigated.

The electrical discharge was ignited in a stainless steel tapered chamber of a nominal volume of m3 immersed inside a water-cooled coil capable of delivering a magnetic field of strength B Author: Abdilrida S. Hasaani. atmospheric air glow discharge with water electrode using Rayleigh scattering Citation for published version (APA): Verreycken, T., Gessel, van, A.

H., Pageau, A., & Bruggeman, P. Validation of gas temperature measurements by OES in an atmospheric air glow discharge with water electrode using Rayleigh by: Chapter 9 Multiple choice. STUDY. PLAY. Is a reactive form of oxygen produced by subjecting molecular oxygen to an electrical discharge.

YOU MIGHT ALSO LIKE 87 terms. chapter 9 micro Weber Health Assessment Ch. Assessing Eyes. 42 terms. HESI Grammar Practice. terms. HESI A2 A&P ELSEVIER BOOK. terms. Hesi Entrance Exam. BASIC RESEARCH ON THE CHARACTERISTICS OF A CONSTRICTED PULSED GLOW DISCHARGE By Sean Daniel Andersen A thesis submitted in partial fulfillment of the requirements for the Master of Science in Electrical Engineering Department of Electrical and Computer Engineering Howard R.

Hughes College of Engineering The Graduate CollegeAuthor: Sean Daniel Andersen. of ICP discharge (that means that the electron and ion fluxes do not satisfy the conventionally adopted ambipolarity con-dition), we have shown the presence of vortex currents also in glow discharge plasma, for a short discharge, and vanish-ing of it in the positive column of longer glow discharge.

The paper is organized as follows. Ball lightning is an unexplained atmospheric electrical phenomenon described as luminescent, spherical objects that vary from pea-sized to several meters in usually associated with thunderstorms, the phenomenon is said to last considerably longer than the split-second flash of a lightning bolt.

Some nineteenth century reports describe balls that eventually explode and leave.region. The characteristics of glow discharge (plasma) column were observed influenced with inter- electrode spacing and gas pressure, and the negative glow, Faraday dark and positive column regions are recognized.

(Received September 2, ; accepted Septem ) Keywords: Low pressure plasma, N2 gas breakdown, dc - glow discharge.3 Influence of external magnetic field on the radiation emitted by negative glow Fig.

1 – Experimental set-up. Fig. 2 – The relative variation of the TVI (ΔI/I0) versus magnetic field (B) for different values of discharge potential (U) in the two configurations: a) CMC (central electrode cathode) and b) ICMC (central electrodeanode).