By Topic

IEEE Transactions on Plasma Science

Issue 5 • Oct 1991

Filter Results

Displaying Results 1 - 25 of 44
  • Experimental investigations of feedback circuits for suppressing resistive wall modes

    Publication Year: 1991, Page(s):954 - 958
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    Feedback circuits have been designed and tested which reduce the component of a fluctuating magnetic field normal to a square coil. These circuits, when placed in an array covering a toroidal plasma, may be a practical alternative to a perfectly conducting shell for stabilizing resistive wall modes View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurements of vacuum field emission from bio-molecular and semiconductor-metal eutectic composite microstructures

    Publication Year: 1991, Page(s):749 - 756
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (776 KB)

    Designs, calculations, and initial data are presented from a program investigating the use of biomolecular and eutectic composite microstructures as vacuum field-emission cathodes. Calculations, supported by the initial data, indicate that these electron sources should be capable of macroscopic beam current densities, J⩾100 A/cm2, without the formation of a surface plasma. ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optical investigation of arc spot formation on cold cathodes in air

    Publication Year: 1991, Page(s):947 - 953
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1184 KB)

    The column of a high current arc was magnetically blown against a cathode positioned perpendicularly to the arc axis. A linearly increasing voltage was applied to this electrode. It was shown by high-speed photography that the arc spot ignition is initiated by an intensified light emission on the cathode within an area of approximately 40-μm diam. SEM micrographs from the traces produced during... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electron and ion emission from liquid metal surfaces

    Publication Year: 1991, Page(s):746 - 748
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    The application of positive or negative electric fields to small-area liquid metal surfaces leads to very high brightness DC ion or pulsed electron emission. The stabilization of a cone-shaped structure by the balance of electrostatic and surface tensions forces is described. Electron and ion emission occurs by field emission and field evaporation mechanisms View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurement of arc spot formation delay times at cold cathodes in air

    Publication Year: 1991, Page(s):942 - 946
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    The column of a high current arc is magnetically blown against a cathode positioned perpendicularly to the arc axis. A linearly increasing voltage is applied to this electrode. The delay time of the arc spot formation which initiates the arc commutation was measured for smooth electrodes made of Cu, steel, graphite, Mg, and Ce. The cumulative frequency distribution of this delay time was found to ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Plasma-aided manufacturing

    Publication Year: 1991, Page(s):725 - 733
    Cited by:  Papers (51)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (924 KB)

    The present and potential applications of plasma-aided manufacturing are discussed and described. Plasma-aided manufacturing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. Plasma-aided manufacturing has direct applications to semiconductor fabrication... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Technological sources of charged particles with plasma emitters

    Publication Year: 1991, Page(s):743 - 745
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    At present, ion and electron beams, extensively used in industry, usually have a small cross section. Presented are generators of ion and electron flows with a large cross section using plasma emitters. These devices have a wide range of currents and voltages and are designed for metallurgical treatment and microelectronics. The author discusses a technological source of ions based on the vacuum-a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vacuum breakdown on metal surfaces

    Publication Year: 1991, Page(s):690 - 696
    Cited by:  Papers (37)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (908 KB)

    The unipolar arc model is described. Experimental proof that unipolar arcing represents a discharge form which easily leads to explosive plasma formation is provided. Using a laser-produced plasma, it has been demonstrated that unipolar arcs ignite and burn on a nanosecond time scale without any external electric field being applied. Similar unipolar arc craters have been observed on the cathode s... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental investigation of a hydrogen plasma railgun

    Publication Year: 1991, Page(s):935 - 941
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    The plasma velocity and temperature and composition distributions in a hydrogen plasma railgun were measured. Typical velocities near the muzzle were ~95 km/s at an initial capacitor bank stored energy of 4.1 kJ. Temperatures ranged from a peak of ~24000 K in the current-carrying plasma to ~8500 K in the tail. The current-carrying plasma was composed of roughly equal parts of hydrogen and copper o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characterization of electron flow in negative- and positive-polarity linear-induction accelerators

    Publication Year: 1991, Page(s):822 - 830
    Cited by:  Papers (30)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (696 KB)

    The operation of the linear-induction accelerators HELIA and Hermes III was studied in both negative and positive polarities. The experiments in positive polarity have provided a unique opportunity to explore the consequences of multiple-cathode electron emission in magnetically insulated transmission lines. It is maintained that an examination of the total energy-canonical momentum distribution o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Influence of electrode separation on ion density in the vacuum arc

    Publication Year: 1991, Page(s):718 - 724
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    The density of singly ionized chromium shortly before and after forced extinction of vacuum arcs between chromium-copper electrodes was measured by laser-induced fluorescence for 2- and 10-mm contact gaps and currents between 200 A and 1 kA. In all cases studied, the ion density was constant before ramping down to the current and decayed exponentially after current zero. The ion density at current... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Glow discharge cleaning of vacuum switch tubes

    Publication Year: 1991, Page(s):740 - 742
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    To clean the surfaces of parts inside a vacuum-switch tube (VST) the authors propose a technique which generates a glow discharge between the inner electrodes and the copper grid surrounding it. Photographic observation reveals that the glow discharge spreads out and cleans the whole surface inside the VST. A breakdown test between the inner electrodes shows the effect of the cleaning with this te... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vacuum discharge effects in the diodes of high-current electron accelerators

    Publication Year: 1991, Page(s):683 - 689
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    The processes occurring in the diodes of high-current electron accelerators which affect the electron beam structure are discussed. Two types of diodes are analyzed: planar diodes producing large cross-section beams, and magnetically insulated diodes producing cylindrical beams. The effects considered are: the screening effect, the effect of touches, the relay effect, the ring effect, etc. They ar... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cross-correlation-based method for determining the position and velocity of a railgun plasma armature from B-dot probe signals

    Publication Year: 1991, Page(s):926 - 934
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (580 KB)

    A method of determining the position and velocity of a plasma armature from B-dot probe signals is presented. It utilizes the physical processes governing the plasma armature current density to model the leading edge of the armature as a unit step function. This model of the current profile is convolved with the impulse response of the probe and compared with B-dot probe data via a local-area cros... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A sequential plasma focus

    Publication Year: 1991, Page(s):912 - 919
    Cited by:  Papers (51)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (540 KB)

    Shadowgraph studies suggest that a target disk placed downstream of the anode of a plasma focus may become an auxiliary anode producing a second focusing event when the current sheet climbs over it after the first focus event. A model is put forth in which each event is assumed to comprise three phases: an axial phase, a radial phase, and a radial extension or expanded column phase. This model pro... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Long-delayed reignitions of the vacuum arc

    Publication Year: 1991, Page(s):894 - 905
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1168 KB)

    Peculiar long-delayed (up to 200 μs) breakdowns at voltages much below the interelectrode gap static breakdown limit have been observed following the forced extinction of the cathode-governed vacuum arc. The overall probability of such breakdowns has been determined in several combinations of the test voltage (5, 10, and 15 kV) and chopped arc current amplitude (50, 100, and 150 A). A time dist... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vacuum ion source diagnostics at the Tokyo Institute of Technology

    Publication Year: 1991, Page(s):814 - 821
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (596 KB)

    After a brief review of various diagnostics for vacuum ion sources measured data are presented for the particle distributions within the anode/cathode gap regions using passive spectroscopy, active laser interferometry, and resonant laser-induced fluorescence, while the extracted ion beams were observed by particle track detectors of both time-integrated and time-resolved types. Also measured were... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vacuum arc ion charge-state distributions

    Publication Year: 1991, Page(s):713 - 717
    Cited by:  Papers (173)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    Vacuum arc ion charge-state spectra have been measured for a wide range of metallic cathode materials. The charge-state distributions were measured using a time-of-flight diagnostic to monitor the energetic ion beam produced by a metal vapor vacuum arc ion source. Data were obtained for 48 metallic cathode elements: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radiative aspects of the ablation-stabilized arc in polyethylene tube

    Publication Year: 1991, Page(s):879 - 884
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    The arcs burning through polyethylene tubes are observed photographically and spectroscopically. The arc currents are 5~15 A DC. The tubes are of 2~6-mm inner diameter and are 15 mm in length. Color photographs of the arc reveal that the arc column consists of three emission regions: a red-colored core and blue-colored and orange-colored layers. The spectral intensity of the arc column is surveyed... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Miniaturized liquid metal ion sources (MILMIS)

    Publication Year: 1991, Page(s):790 - 799
    Cited by:  Papers (5)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (948 KB)

    Introductory remarks are given on ion sources, and basic features of liquid-metal ion sources (LMISs) are outlined. A special by-product of field-emission electric space propulsion by a liquid metal ion thruster is the slit emitter, which may be qualified as a semiminiaturized LMIS. The state-of-the-art technology of field-emitter arrays common in vacuum microelectronics is presented in view of th... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Cowling `limiting-points' proof of his anti-dynamo theorem

    Publication Year: 1991, Page(s):862 - 865
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    According to the Cowling antidynamo theorem, a self-excited steady-state dynamo in a conducting fluid cannot be axisymmetric. One of his proofs, which is based on the impossibility of the existence of limiting points, was referred to by I. Alexeff (ibid., vol.17, pp.282-283, Apr. 1989) who showed that it is not valid in diffuse plasmas. It is here shown that Cowling's limiting-points proof, which ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Expansion of hydrogen arcs driven by oscillating currents

    Publication Year: 1991, Page(s):959 - 967
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (640 KB)

    Calculations of the arc channel radius using the arc current as the independent variable are presented and discussed. Previously reported experimental results for the expansion of ~300-A to ~3000-A discharges in 460-torr hydrogen are compared with the theoretical radius calculations presented. Errors introduced in the calculated channel radius are investigated by first assuming the channel conduct... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Investigation of plasma opening switch conduction and opening mechanisms

    Publication Year: 1991, Page(s):757 - 766
    Cited by:  Papers (48)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (912 KB)

    Plasma opening switch techniques have been developed for pulsed power applications to exploit the advantages of electrical energy storage in a vacuum inductor compared to conventional, capacitive-based energy storage. Experiments are described that demonstrate the successful application of these techniques in conduction time ranges from 50 ns to over 1 μs. Physics understanding of the conductio... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vacuum arc deposition of carbon thin films in a low pressure of hydrogen

    Publication Year: 1991, Page(s):734 - 739
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    Results on the vacuum arc deposition (VAD) of thin carbon films on silicon, tungsten, and nickel are presented for different hydrogen pressures in the arc chamber. Raman and Auger electron spectroscopy and SEM analysis show that a large variety of film structures can be obtained. Highly oriented pyrolytic graphite is formed at high hydrogen pressure and low substrate temperature. Vacuum deposition... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Macroscopic models of internal dynamics of electrical discharges

    Publication Year: 1991, Page(s):697 - 704
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    The existence of thresholds for electrical discharge onset suggests a functional relation between macroscopic resistivity and current. At low current, the resistivity should be inversely proportional to the magnitude of the current. Macroscopic models which employ this scaling predict many empirically observed properties of transient electrical discharges such as: (i) thresholds for the onset of c... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Plasma Sciences focuses on plasma science and engineering, including: magnetofluid dynamics and thermionics; plasma dynamics; gaseous electronics and arc technology.

 

 

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Steven J. Gitomer, Ph.D.
Senior Scientist, US Civilian Research & Development Foundation
Guest Scientist, Los Alamos National Laboratory
1428 Miracerros Loop South
Santa Fe, NM  87505  87505  USA
tps-editor@ieee.org
Phone:505-988-5751
Fax:505-988-5751 (call first)