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in subjects: "Plasma Production"

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Studies of the Formation of Field Reversed Plasma by a Magnetized Co-Axial Plasma Gun

The gun injects axially into a drift tank followed by a magnetic mirror. For the experiments reported here, only the guide coils outside the vacuum vessel and solenoids on the plasma gun electrodes were used; the mirror coil was not energized. A stainless steel flux conserver is placed in the mirror throat to prevent the plasma from contacting the nonconducting vacuum wall in the region of the mirror. An axis encircling array of magnetic loop probes includes four diamagnetic loops and a loop wh… more

Date: May 28, 1980

Creator: Turner, W. C.; Granneman, E. H. A.; Hartman, C. W.; Prono, D. S.; Taska, J. & Smith, A. C., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

VUV production from a ferrite-driven flash-pumped system

The relative spectral emission as a function of wavelength in the 1200--2900 {Angstrom} region is measured for a vacuum UV flash device whose discharge is initiated by a high resistance formed-ferrite rod. The device is studied because of its usefulness in the optical pumping of large volume laser systems.

Date: January 1, 1991

Creator: Sze, R.C. (Los Alamos National Lab., NM (United States)) & Sentis, M. (Institut de Mecanique des Fluides, 13 - Marseille (France))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mechanical design for TMX injector system

The injector system for the Tandem Mirror Experiment (TMX) contains the components required to create and maintain a high-temperature, high-density plasma. These components include a streaming-plasma gun in each of the plug tanks to form the target-plasma, 24 neutral-beam source modules for injecting neutral deuterium atoms to heat and replace losses from the plasma, and a gas box system that applies a streaming cold gas to the plasma to stabilize it. This paper discusses the mechanical design … more

Date: October 17, 1977

Creator: Calderon, M.O.; Chen, F.F.K. & Denhoy, B.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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DuoPIGatron ion sources for PLT injectors

Plasma heating requirements for the Princeton Large Torus (PLT) are set at about 1 MJ total beam energy for 3 MW beam power of energetic hydrogen (or deuterium) neutrals at 40 keV. To fulfill this design goal from four neutral beam injectors, the duoPlGatron ion source originally developed at ORNL has been modified, developed, and scaled-up to versions with 20-cm and/or 22-cm grid diameters. Utilizing the multipole line cusp magnetic field confinement for the ionizing electrons and created Phil… more

Date: January 1, 1977

Creator: Tsai, C. C.; Stirling, W. L.; Haselton, H. H.; Davis, R. C. & Schechter, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Methods for independent plasma production and beam injection for H/sup +/. -->. H/sup -/ surface conversion

Based on the Oak Ridge National Laboratory (ORNL) source development program, ways to create a uniform and dense plasma are briefly reviewed. The positive ions so created will be accelerated towards a surface convertor for producing negative ions. The convertor will be used for reducing the electrons in the extraction region. The significant results and features of this study are presented.

Date: January 1, 1977

Creator: Tsai, C C; Stirling, W L & Davis, R C

Item Type: Article

Partner: UNT Libraries Government Documents Department

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RF ion source development for neutral beam application

At Lawrence Berkeley Laboratory, a 24 x 24 cm/sup 2/ RF source has been tested with beam acceleration. Recently, we have been investigating the characteristics of plasmas generated with different kinds of antenna coatings. The antenna coil was installed inside a cylindrical multicusp source (20-cm diam by 24-cm long) and was driven by a 500 W amplifier. A tiny light bulb filament was used to start a background plasma. The RF was then switched on and a steady-state hydrogen plasma of moderate de… more

Date: November 1, 1983

Creator: Leung, K. N.; Ehlers, K. W.; Kippenhan, D. & Vella, M. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design and fabrication of a 30 second pulsed plasma generator

The design and fabrication techniques for a large hybrid magnetic cusp plasma generator developed for 30 sec pulse length are described. Included are the magnetic cusp geometry features, water cooling characteristics, filament structures, and the high energy density actively cooled anode and electron dump employed.

Date: October 1, 1983

Creator: Biagi, L. A.; Ehlers, K. W.; Lietzke, A. F.; Matuk, C. A.; Maruyama, Y.; Paterson, J. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Plasma production and flow in negative ion beams

Plasma generated in low-density vapor by a negative ion beam has been studied experimentally and computationally. We show that space charge neutralization of the beam occurs at very low vapor density, and that correspondingly the electron density may be much less than the beam and plasma ion densities. When there is a large local gas density, as in a charge changing cell, the resulting high electron density is also localized to the same region. Therefore, very few electrons will reach a negativ… more

Date: September 21, 1977

Creator: Anderson, O. A. & Hooper, E. B. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electrical characterization of rf plasmas

Radio-frequency (rf) electrical sources are commonly used to generate plasmas for processing of industrial materials and for related experimental work. Published descriptions of such plasmas usually include generator-power measurements, and occasionally include plasma dc-bias measurements. One or both of these quantitites are also used in industrial feedback ccontrol systems for setpoint regulation. Recent work at Sandia an elsewhere with an experimental rf discharge device (the GEC RF Referenc… more

Date: August 1, 1991

Creator: Miller, P.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design and fabrication of a large rectangular magnetic cusp plasma source for high intensity neutral beam injectors

The design and fabrication techniques for a large, rectangular magnetic bucket plasma source are described. This source is compatible with the accelerator structures for the TFTR and DIII neutral-beam systems.

Date: November 1, 1979

Creator: Biagi, L. A.; Berkner, K. H.; Ehlers, K. W.; Paterson, J. A. & Porter, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Volumetric plasma source development and characterization.

The development of plasma sources with densities and temperatures in the 10{sup 15}-10{sup 17} cm{sup -3} and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases t… more

Date: September 1, 2008

Creator: Crain, Marlon D. (National Security Technologies, LLC, Las Vegas, NV); Maron, Yitzhak (Weizmann Institute of Science, Rehovot, Israel); Oliver, Bryan Velten; Starbird, Robert L. (National Security Technologies, LLC, Las Vegas, NV); Johnston, Mark D.; Hahn, Kelly Denise et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Measurment of Depositing and Bombarding Species Involved in the Plasma Production of Amorphous Silicon and Silicon/Germanium Solar Cells: Annual Technical Report, 1 June 2002 - 31 May 2005

The objective of this study is to measure the molecular species that lead to the growth of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (..mu..c-Si) photovoltaic (PV) devices from RF discharges. Neutral radicals produce most of the film growth during this PV-device production, and, by implication, radicals primarily determine the device structure and electrical characteristics. The most important feature of the present experiment is thus the measurement of neutral-radica… more

Date: June 1, 2006

Creator: Gallagher, A.; Rozsa, K.; Horvath, P. & Kujundcik, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A study of vacuum arc ion velocities using a linear set of probes

The most likely velocity of ions moving away from vacuum arc cathode spots was measured using a set of probes along the path of plasma expansion. The goal was to determine how much, if any, change of the ion drift velocity occurs in the expanded plasma. The arc discharge current was perturbed to create plasma density markers whose travel is picked up by the set of probes. It was found that the perturbation with current oscillations did not result in consistent data because ion current maxima an… more

Date: July 15, 2008

Creator: Hohenbild, Stefan; Grubel, Christoph; Yushkov, Georgy Yu.; Oks, Efim M. & Anders, Andre

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of a plasma retropulse shutter for Shiva and Nova

A plasma shutter is being developed for a Nd:glass laser fusion system which, at an output spatial filter pinhole, produces a plasma of 10/sup 21/ cm/sup -3/ to block target-reflected light from reentering the laser. A pulser using low-inductance capacitors and elastomer dielectric is switched with uv preilluminated railgaps to resistively heat a wire producing a plasma. The plasma generated within a nozzle and configured in a railgun geometry is projected across the optical beam path at 3.9 cm… more

Date: September 26, 1979

Creator: Bradley, L. P.; Orham, E. L.; Stowers, I. F. & Koert, P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Dense Z-pinch plasmas

Early researchers recogniZed the desirable features of the linear Z-pinch configuration as a magnetic fusion scheme. In particular, a Z-pinch reactor might not require auxiliary heating or external field coils, and could constitute an uncomplicated, high plasma ..beta.. geometry. The simple Z pinch, however, exhibited gross MHD instabilities that disrupted the plasma, and the linear Z pinch was abandoned in favor of more stable configurations. Recent advances in pulsed-power technology and an a… more

Date: July 12, 1985

Creator: Shlachter, J. S.; Hammel, J. E. & Scudder, D. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of rf plasma generators for neutral beams

The development of low frequency (1-2 MHz) rf plasma generators for high power neutral beam applications is summarized. Immersed couplers from one to three turns were used. Acceptable plasma profiles, less than or equal to 15% max/min, were obtained in a variety of field-free magnetic bucket and magnetic filter-bucket sources, with 10 x 10 cm or 10 x 40 cm extraction areas. Hydrogen beam properties were measured with a 7 x 10 cm accelerator operated at 80 kV. Atomic fraction and power efficienc… more

Date: October 1, 1984

Creator: Vella, M. C.; Ehlers, K. W.; Kippenhan, D.; Pincosy, P. A.; Pyle, R. V.; DiVergilio, W. F. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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High efficiency ionizer using a hollow cathode discharge plasma

A proposal for an ionizer using a hollow cathode discharge plasma is described. Ionization is via the very high current density electron beam component in the plasma, as well as from charge exchange with plasma ions. Extraction of a He/sup +/ current corresponding to approximately 50% of the incoming atomic beam flux should be possible.

Date: January 1, 1984

Creator: Alessi, J.G. & Prelec, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Institutional research and development, FY 1988

The Laboratory's Institutional Research and Development (IR and D) Program was established in 1984 to foster exploratory work to advance science and technology, disciplinary research to develop innovative solutions to support our national defense and energy missions. In FY 1988, the IR and D Program was funded by a 2% assessment on the Laboratory's operating budget. Our policy is to use these funds for researching innovative ideas in LLNL's areas of expertise and for developing new areas of exp… more

Date: January 1, 1988

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Tearing-mode stability of a forming Spheromak plasma

The results of numerical calculations of ..delta..' for a class of equilibria typical of those encountered during the early formation stage of the S1 Spheromak are presented. The equilibrium plasma is assumed to be cylindrically symmetric and pressureless. It encloses a current carrying perfect conductor (flux core) and is surrounded by a vacuum with zero longitudinal field. Stability boundaries in the space formed by the equilibrium parameters are mapped. The plasma is tearing mode stable prov… more

Date: October 1, 1981

Creator: Heidbrink, W. W.; Jardin, S. C. & Chance, M. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Design and fabrication of a large magnetic cusp type of plasma generator for the production of negative ions

The design and fabrication techniques for a large magnetic bucket type of plasma source designed for the production of negative ions by surface conversion are described. These include the design of a converter structure, cesium oven and injector, variable aperture electrode, accelerator section as well as the features of the magnetic cusp geometry employed.

Date: October 1, 1981

Creator: Biagi, L. A.; Ehlers, K. W.; Leung, K. N.; Matuk, C. A.; Moon, S. D. & Paterson, J. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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H/sup -/ production in a multicusp microwave plasma

An experiment was undertaken to examine H/sup -/ production by volume processes in a multicusp microwave discharge, part of the cusp field being enhanced to produce an ECR (electron cyclotron resonance), that would also isolate the hotter plasma formed there. This arrangement is analogous to the ''magnetic filters'' used in some other negative ion sources. This work describes the experiment set up and the results obtained, which are a survey of the behavior of this type of device. Also included… more

Date: March 1, 1985

Creator: Trow, J.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Compact 5 x 10/sup 12/ AMP/SEC rail-gun pulser for a laser plasma shutter

We have developed a rail-gun plasma source to produce a plasma of 10/sup 12/cm/sup -3/ particle density and project it with a velocity of 3.9 cm/..mu..s. This device will be used in a output spatial filter of Nova to project a critical density plasma across an optical beam path and block laser retroreflected light. The object of this paper is to describe the design of a pulser appropriate to the Shiva laser fusion facility, and to describe the preliminary design of a higher current prototype pu… more

Date: June 12, 1979

Creator: Bradley, L. P.; Orham, E. L. & Stowers, I. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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System requirements for the Los Alamos foil-implosion project

The goal of the Los Alamos imploding foil project is the development of an intense source of soft x rays and hot plasma produced from the thermalization of 1 to 10 MJ of plasma kinetic energy. The source will be used for material studies and fusion experiments. Specifically, thin, current-carrying cylindrical metallic plasmas are imploded via their self-magnetic forces. Features of this project are the use of high-explosive-driven flux-compression generators as the prime power source to achieve… more

Date: January 1, 1983

Creator: Brownell, J.; Bowers, R.; Greene, A.; Lindemuth, I.; Nickel, G.; Oliphant, T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Computer analysis, design and construction of the BNL Mk V magnetron

As part of a program to develop a high energy neutral beam injector for fusion reactor applications, the BNL Neutral Beam Group is studying, among other options, a surface plasma source of the magnetron type. This source has been developed to the point at which a large compact model, known as the Mk V magnetron, has been designed and constructed. The source is designed to operate in the steady state mode and to produce 1-2A of H/sup -/(D/sup -/) ions at 25 kV. Under these conditions, 18 KW of h… more

Date: January 1, 1981

Creator: McKenzie-Wilson, R.B. & Kovarik, V.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department