394 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Plasma Production"

open access

Industrial process driven system requirements for PSII applications

Plasma Source Ion Implantation (PSII) is a room temperature, plasma-based surface enhancement technology which is being commercialized through the efforts of a group of companies. A number of issues are critical to the successful design and operation of a commercial PSII system. These include overall vacuum system design, plasma source requirements and plasma-target interaction considerations, pulsed, high voltage sub-system (typically referred to as modulator) requirements, and target requirem… more

Date: October 1, 1997

Creator: Munson, C.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Deposition of mullite and mullite-like coatings on silicon carbide by dual-source metal plasma immersion. Topical report, October 1995--September 1996

Mullite and mullite-like coatings on silicon carbide have been produced by a Metal Plasma Immersion Ion Implantation and Deposition (Mepiiid) technique based on two cathodic vacuum arc sources and concurrent pulse biasing of the substrate in an oxygen atmosphere. The deposition was carried out at oxygen partial pressures of between 0.66 and 3.33 Pa. The Al:Si ratio in the films varied from 1:1 to 8:1 and was controlled by varying the pulse duration of the separate plasma guns. High bias voltage… more

Date: April 1, 1997

Creator: Brown, I.G. & Monteiro, O.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Progress towards a 20 kV, 2 kA plasma source ion implantation modulator for automotive production of diamond film on aluminum

This paper provides the process requirements and the electrical design topology being developed to facilitate large scale production of amorphous diamond films on aluminum. The patented recipe, that includes other surface modification processes, requires various operational voltages, duty cycles, and current load regimes to ensure a high quality film. It is desirable to utilize a common modulator design for this relatively low voltage recipe. Processing may include target part cleaning, ion imp… more

Date: November 1, 1996

Creator: Reass, W.A.; Munson, C.A.; Malaczynski, G. & Elmoursi, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

LLL LASER PROJECTS REPORT NO. 2.

No Description Available.

Date: January 1, 1972

Creator: Kachen, G.I. & Shaw, G. (eds.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ion Bernstein wave heating research

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW`s low phase velocity ({omega}/k{sub {perpendicular}} {approx} V{sub Ti} {much_lt} V{sub {alpha}}) greatly reduces the otherwise serious wave abs… more

Date: March 1, 1992

Creator: Ono, Masayuki

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ICRF heating during DT experiments on TFTR: System improvements and results

In order to carry out a program of ICRF experiments in deuterium- tritium plasmas on the TFTR device a series of technical improvements have been made to the ICRF system. These improvements allow more flexible and reliable operation of the system which is crucial for the limited number of tritium discharges available. During the last year circuitry has been installed to feedback the plasma position on antenna loading, to lock the phase between antenna elements, and to detect arcs from the secon… more

Date: August 1, 1994

Creator: Wilson, J. R.; Hosea, J. C. & Larue, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Numerical solution of a tunneling equation

A numerical method is presented to solve mode conversion equations resulting from the use of radio frequency (rf) waves to heat plasmas. The solutions of the mode conversion equations contain exponentially growing modes, and ordinary numerical techniques give large errors. To avoid the unphysical growing modes, a set of boundary conditions are found, that eliminate the unphysical modes. The mode conversion equations are then solved with the boundary conditions as a standard two-point boundary v… more

Date: April 1, 1994

Creator: Wang, C. Y.; Carter, M. D.; Batchelor, D. B. & Jaeger, E. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ICRF-induced DD fusion product losses in TFTR

When ICRF power is applied to TFTR plasmas in which there is no externally-supplied minority species, an enhanced loss of DD fusion products results. The characteristics of the loss are consistent with particles at or near the birth energy having their perpendicular velocity increased by the ICRF such that those near the passing/trapped boundary are carried into the first orbit loss cone. A rudimentary model of this process predicts losses of a magnitude similar to those seen. Extrapolations ba… more

Date: October 1, 1994

Creator: Darrow, D. S.; Zweben, S. J. & Budny, R. V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Statistical approach to LHCD modeling using the wave kinetic equation

Recent work has shown that for parameter regimes typical of many present day current drive experiments, the orbits of the launched LH rays are chaotic (in the Hamiltonian sense), so that wave energy diffuses through the stochastic layer and fills the spectral gap. We have analyzed this problem using a statistical approach, by solving the wave kinetic equation for the coarse-grained spectral energy density. An interesting result is that the LH absorption profile is essentially independent of bot… more

Date: April 1, 1993

Creator: Kupfer, K.; Moreau, D. & Litaudon, X.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ITER ECH launcher options for start-up assist, bulk heating, and EC current drive experiments

Electron Cyclotron Heating (ECH) is proposed for providing plasma start-up, bulk heating, current drive, and other applications on the International Tokamak Experimental Reactor (ITER) project. The requirements for ECH power launching systems for ITER have been investigated, and several possible configurations that have been devised are described in this report. The proposed launcher designs use oversized circular corrugated waveguides that make small penetrations through the blanket modules an… more

Date: March 1, 1994

Creator: Bigelow, T. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Computer calculations of x-ray production by laser-produced plasmas

No Description Available.

Date: October 27, 1972

Creator: Birkett, R.E. & Zimmerman, G.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ECR etching of GaP, GaAs, InP, and InGaAs in Cl{sub 2}/Ar, Cl{sub 2}/N{sub 2}, BCl{sub 3}/Ar, and BCl{sub 3}/N{sub 2}

Electron cyclotron resonance (ECR) etching GaP, GaAs, InP, and InGaAs are reported as a function of percent chlorine-containing gas for Cl{sub 2}/Ar, Cl{sub 2}/N{sub 2}, BCl{sub 3}/Ar, and BCl{sub 3}N{sub 2} plasma chemistries. GaAs and GaP etch rates were faster than InP and InGaAs, independent of plasma chemistry due to the low volatility of the InCl{sub x} etch products. GaAs and GaP etch rates increased as %Cl{sub 2} was increased for Cl{sub 2}/Ar and Cl{sub 2}/N{sub 2} plasmas. The GaAs an… more

Date: June 1, 1996

Creator: Shul, R. J.; Baca, A. G.; Rieger, D. J.; Hou, H.; Pearton, S. J. & Ren, F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analysis of filtered silicon diode data from the MAGO II and MAGO III experiments

The magnetic compression (MAGO) experiments were conceived by the All-Russia Scientific Institute for Experimental Physics (VNIIEF) several years ago, and only recently has Los Alamos National Laboratory (LANL) participated in joint US/Russian experiments intended to combine the advanced US diagnostic technology with the unsurpassed explosive pulsed power technology fielded by VNIIEF. On two of the four joint LANL/VNIIEF magnetized plasma generation (MAGO) experiments fielded thus far, filtered… more

Date: September 1, 1996

Creator: Kirkpatrick, Ronald C. & Idzorek, George

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

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

open access

Magnetized target fusion: An ultra high energy approach in an unexplored parameter space

Magnetized target fusion is a concept that may lead to practical fusion applications in a variety of settings. However, the crucial first step is to demonstrate that it works as advertised. Among the possibilities for doing this is an ultrahigh energy approach to magnetized target fusion, one powered by explosive pulsed power generators that have become available for application to thermonuclear fusion research. In a collaborative effort between Los Alamos and the All-Russian Scientific Institu… more

Date: December 31, 1994

Creator: Lindemuth, I. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Conversion of the four-strap array in DIII-D to a tunable traveling wave antenna

The in situ conversion of the two-standing wave resonator driven four-strap array in DIII-D to a new type of traveling wave antenna (TWA) is introduced. First observations are reported on (1) broad frequency range turnability; (2) narrow frequency band phase control; (3) single pass transmission loss and modification caused by resistive and reactive sheet simulators of plasma loading; and (4) recirculating power resonance and gain in a traveling wave resonator (TWR) driven TWA.

Date: April 1993

Creator: Phelps, D. A.; Moeller, C. P.; Petty, C. C.; Pinsker, R. I.; Ryan, P. M.; Goulding, R. H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

PBX-M ion Bernstein wave heating overview

A high power ion Bernstein wave heating system has been introduced on PBX-M for heating and for controlling the plasma pressure profile in an effort to achieve the stable high beta ``second stability`` regime. The pressure profile can be controlled through local bulk ion heating as well as density profile control. In bean-shaped plasmas with plasma currents range from 180 kA to 250 kA, good ion heating up to the highest, applied rf power, ({approx}700 kW) has been observed. The observed broaden… more

Date: April 1, 1993

Creator: Ono, M.; Chu, T. K.; Hermann, H.; LeBlanc, B.; Tighe, W.; Bell, R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Experiment and simulation of hole-coupled resonator modes with a CW HeNe laser

The Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Laboratory at Lawrence Berkeley Laboratory will operate from 3 - 50 {mu}m and use all-metal optics. This choice of optics allows for broad tuning and has excellent power-handling capabilities. A hole-coupling approach for the optical resonator was adopted after extensive computer simulations verified that it fully met the design requirements. To bench-test the simulations we have carried out a scaled cavity experiment u… more

Date: August 1, 1992

Creator: Leemans, W. P.; Xie, M.; Edighoffer, J. A.; Wallace, E.; Kim, K. J. & Chattopadhyay, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Control of the current density profile with lower hybrid current drive on PBX-M

Lower hybrid current drive (LHCD) is being explored as a means to control the current density profile on PBX-M with the goal of raising the central safety factor q(O) to values of 1.5-2 to facilitate access to a full-volume second stable regime. Initial experiments have been conducted with up to 400 kW of 4.6 GHz LH power in circular and indented plasmas with modest parameters. A tangential-viewing two-dimensional hard x-ray imaging diagnostic has been used to observe the bremsstrahlung emissio… more

Date: July 1, 1993

Creator: Bell, R. E.; Bernabei, S.; Chu, T. K.; Gettelfinger, G.; Greenough, N.; Hatcher, R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microwave scattering from TAE modes. Progress report, [August 1991--September 1992]

No Description Available.

Date: September 28, 1992

Creator: Vahala, L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Review: engineering particles using the aerosol-through-plasma method

For decades, plasma processing of materials on the nanoscale has been an underlying enabling technology for many 'planar' technologies, particularly virtually every aspect of modern electronics from integrated-circuit fabrication with nanoscale elements to the newest generation of photovoltaics. However, it is only recent developments that suggest that plasma processing can be used to make 'particulate' structures of value in fields, including catalysis, drug delivery, imaging, higher energy de… more

Date: January 1, 2009

Creator: Phillips, Jonathan; Luhrs, Claudia C & Richard, Monique

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

One dimensional global and local solution for ICRF heating

A numerical code GLOSI [Global and Local One-dimensional Solution for Ion cyclotron range of frequencies (ICRF) heating] is developed to solve one-dimensional wave equations resulting from the use of radio frequency (RF) waves to heat plasmas. The code uses a finite difference method. Due to its numerical stability, the code can be used to find both global and local solutions when imposed with appropriate boundary conditions. Three types of boundary conditions are introduced to describe wave sc… more

Date: February 1, 1995

Creator: Wang, C. Y.; Batchelor, D. B.; Jaeger, E. F. & Carter, M. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

TFTR Ion Cyclotron Range of Frequencies (ICRF) experimental data analysis collaboration. Annual progress report, December 1, 1992 to November 30, 1993

The research performed under this grant during the past year has been concentrated on two TFTR tokamak ICRF (Ion Cyclotron Range of Frequencies) coupling, and heating issues. This includes a {open_quotes}3-D{close_quotes} coupling analysis of the TFTR ICRF cavity-backed coil antennas to plasma edge profiles including the Faraday shield blade angle and fast wave coupling for heating and current drive; TFTR ICRF full-wave field solutions, heating analyses for the D-T supershot; and the effects of… more

Date: December 1, 1993

Creator: Scharer, J. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

MHD simulations of DC helicity injection for current drive in tokamaks

MHD computations of DC helicity injection in tokamak-like configurations show current drive with no ``loop voltage`` in a resistive, pressureless plasma. The self-consistently generated current profiles are unstable to resistive modes that partially relax the profile through the MHD dynamo mechanism. The current driven by the fluctuations leads to closed contours of average poloidal flux. However, the 1% fluctuation level is large enough to produce a region of stochastic magnetic field. A limit… more

Date: December 1, 1994

Creator: Sovinec, C. R. & Prager, S. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department