38 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Doublet Reactors"  
Results: 1 - 24 next
open access

Radiation Shielding Design Considerations for Doublet III

Description: Calculations and measurements were made of the bremsstrahlung (x-ray) doses resulting from runaway electron shots at Doublet III. The analysis considered direct, wall-scattered, and skyshine contributions. Reasonably good agreement was obtained between calculations and measurements. The x-ray dose in the control room was about 1 mR per runaway shot, while that at the north boundary was undetectable, with a calculated value of 0.05 mR per shot. These low doses attest to the adequacy of the 2 ft … more
Date: June 1, 1980
Creator: Engholm, B. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Alfven wave stability in D-III-D

Description: Within the framework of the global Alfven eigenmode theory in a cylindrical background plasma, I examine the excitation of global Alfven eigenmodes by intense neutral beam injection in the D III-D tokamak operating at General Atomics. I have considered two separate sets of experimental conditions, a low power'' set of cases using 10MW of hydrogen beams, and a high power'' shot of 20MW of deuterium beams. My results are particularly sensitive to the background density profile. For parabolic back… more
Date: September 1, 1989
Creator: Campbell, R.B. (Lawrence Livermore National Lab., CA (USA)) & Samec, T.K. (TRW, Inc., Redondo Beach, CA (USA))
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Doublet III neutral beam injector test tank cryopanel design

Description: A simple condensing cryopanel has been designed for the Doublet III neutral beam test tank with a 320,000 liters per second pumping capacity for hydrogen. This maintains a vacuum in the test tank which simulates the Doublet III vessel, 1.3 x 10/sup -3/ Pa (approx.10/sup -5/ torr). The hydrogen gas load comes from the beam striking the test tank calorimeter and amounts to about 7.2 torr liters per second. The cryopanel is cylindrical shaped with a liquid helium (LHe) surface that pumps through l… more
Date: March 1, 1980
Creator: Doll, D.W.; Kamperschroer, J.H. & Arend, P.V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Application of an array processor to the analysis of magnetic data for the Doublet III tokamak

Description: Discussed herein is a fast computational technique employing the Floating Point Systems AP-190L array processor to analyze magnetic data for the Doublet III tokamak, a fusion research device. Interpretation of the experimental data requires the repeated solution of a free-boundary nonlinear partial differential equation, which describes the magnetohydrodynamic (MHD) equilibrium of the plasma. For this particular application, we have found that the array processor is only 1.4 and 3.5 times slowe… more
Date: August 1980
Creator: Wang, T. S. & Saito, M. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Modification of Doublet III to a large Dee facility

Description: The Doublet III facility represents a unique opportunity to convert an existing device to a powerful test bed for FED design and operation issues. Such a conversion is made possible by virtue of the demountability of the devices toroidal field coils. Doublet III can be partially disassembled then reassembled with a large dee-shaped vacuum vessel and associated poloidal coils and structure. Doublet III presently possesses or is acquiring adequate auxiliary heating (14 MW of neutral beams and 2 M… more
Date: October 1, 1981
Creator: Davis, L. G. & Rawls, J. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Properties of diverted plasmas with magnetically expanded flux surfaces

Description: Vertical elongated 1.3:1 elliptical plasmas in which the outermost flux surfaces are magnetically expanded and diverted by external coils into the lower half of the Doublet III vacuum vessel are described. Approximately 5 cm of the nominal 45 cm plasma minor radius is diverted to the lower chamber. The diverted flux is expanded by more than a factor of ten before reaching the vessel wall. Photographic measurements show diffused hydrogen recycling light in the lower half of the vessel, with grea… more
Date: July 1, 1980
Creator: Ali Mahdavi, M.; Ohyabu, N. & Baker, D.R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energy confinement in Doublet III with high-Z limiters

Description: This report describes the experimental measurements and data analysis techniques used to evaluate the energy confinement in noncircular plasmas produced in Doublet III. Major aspects of the confinement measurements and analysis techniques are summarized. Machine parameters, diagnostic systems and discharge parameters relavent to the confinement measurements are given. Magnetic analysis techniques used to determine the plasma shape are reviewed. Scaling of the on-axis values of electron temperat… more
Date: February 1, 1980
Creator: Marcus, F. B.; Adcock, S. J.; Baker, D. R.; Blau, F. P.; Brooks, N. H.; Chase, R. P. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The DIII-D summary contribution to the final INTOR workshop

Description: In SIII-D, good H-mode confinement has been obtained with up to 6 MW of neutral-beam injection (NBI). In this report we summarize the essential features of divertor operation for DIII-D H-mode plasma. Briefly, our measurements show that: Large edge density and temperarture gradients are obtained with scale lengths of a few cm at the midplane; In the steady state, approximately 10-20% of the input power is deposited on the divertor plates in a region that is peaked on the separatrix and extends … more
Date: February 26, 1988
Creator: Hill, D. N.; Allen, S. L.; Brooks, N. H.; Content, D.; DeBoo, J. C.; Gohil, P. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Shaping and characteristics of ohmically heated noncircular plasmas in Doublet III

Description: Ohmically heated dee, droplet and doublet plasmas with vertical elongations of up to 3.2 have been produced in Doublet III. Doublet configurations are now obtained by controlled merging of the two current channels of a droplet discharge. All discharges have low levels of impurities and central radiated power and achieve high density relative to B/sub T//R scaling. The energy confinement follows the standard circular cross-section Alcator scaling law. The lack of significant improvement in the c… more
Date: June 1, 1980
Creator: Wesley, J.C.; Angel, T. & Armentrout, C.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electron-cyclotron-heating results on JFT-2, and their implications for the Doublet III ECH design

Description: Electron cyclotron heating experiments are described in which 28 GHz microwave power is injected into the JFT-2 tokamak. Ordinary mode power injected from the low field side increased the central electron temperature from 600 eV to 1000 eV with 110 kW, for densities below the ordinary mode cutoff density of 1.0 x 10/sup 13/ cm/sup -3/. Extraordinary mode power launched obliquely from the high field side increased the temperature from 600 eV to 1200 eV with 85 kW, for densities well below the ex… more
Date: March 1, 1982
Creator: Prater, R. & Moeller, C.P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design of a dee vacuum vessel for Doublet III

Description: The Big Dee modification project has completed the basic physics design and conceptual engineering design phase and is beginning detailed engineering. The project is funded in FY83 for completing most of the detailed design and placing orders for long lead components and systems. This paper summarizes the conceptual engineering design, especially of the vessel itself.
Date: January 1, 1983
Creator: Davis, L. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

8MVA modulator/regulator for neutral beams

Description: This paper describes very generally the modulator/regulator (Mod/Reg) being built for Transrex by Systems, Science and Software for use on the neutral beam power supplies that Transrex is building for General Atomic Company to power the neutral beam heating systems that will be used on the Doublet III fusion device. The Mod/Reg is required to provide an 80 kV, 100 A pulse for a second every 90 sec. The voltage is to be regulated to 3%, and in case of fault the pulse must be interrupted within 1… more
Date: May 1980
Creator: Remsen, D. B., Jr. & Overett, Trevor H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Practical aspects of a 2-D edge-plasma model

Description: The poloidal divertor configuration is considered the most promising solution to the particle and energy exhaust problem for a tokamak reactor. The scrape-off layer plasma surrounding the core and the high-recycling plasma near the divertor plates can be modelled by fluid equations for particle, momentum and energy transport. A numerical code (B2) based on a two-dimensional multi-fluid model has been developed for the study of edge plasmas in tokamaks. In this report we identify some key featur… more
Date: July 1, 1989
Creator: Rensink, M. E.; Hill, D. N.; Porter, G. D.; Braams, B. J. (Lawrence Livermore National Lab., CA (USA) & Princeton Univ., NJ (USA). Plasma Physics Lab.)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Conceptual design summary for modifying Doublet III to a large dee-shaped configuration

Description: The Doublet III tokamak is to be reconfigured by replacing its indented (doublet) vacuum vessel with a larger one of a dee-shaped cross section. This change will permit significantly larger elongated plasmas than is presently possible and will allow higher plasma current (up to 5 MA) and anticipated longer confinement time. Reactor relevant values of stable beta and plasma pressure are predicted. This modification, while resulting in a significant change in capability, utilizes most of the exis… more
Date: May 1, 1983
Creator: Davis, L. G.; Gallix, R.; Luxon, J. L.; Mahdavi, M. A.; Puhn, F. A.; Rock, P. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Applying process-control techniques to a research environment: on-line controls and instrumentation for Doublet III fusion project

Description: The system design is given in terms of the following: (1) conventional aspects, (2) architecture, (3) electronic interfaces, (4) operator interfaces, (5) unconventional aspects, (6) electrical energy, (7) electrical noise, (8) operating flexibility, and (9) command procedure development. (MOW)
Date: September 1, 1983
Creator: Drobnis, D. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Changes in near-surface microstructure of metallic limiters following one year of service in Doublet III

Description: The structural alloys Ta-10W, Mo, and Inconel X-750 were used for plasma limiters during the 3-MW ohmic heating experiments of the Doublet III tokamak. Post-service examinations of these limiters are reviewed. Near-surface melting, cracking, and microstructural changes are shown and discussed. During III service, elements from other metallic components were transported by the plasma and deposited on the limiter surface; significantly, high concentrations of Ni, Fe, Mo, and C were detected in th… more
Date: August 1, 1981
Creator: Trester, P. W.; Sevier, D. L. & Sabado, M. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Upgrade of Doublet III neutral beam injection to long pulse operation

Description: Long pulse physics questions have been raised for auxiliary heated plasma discharges in Tokamaks. A one-second pulse encloses present experiments and is adequate for studying quasi-steady-state operation, whereas, a 5 to 10 second pulse may be required to examine impurity effects of plasma-wall interaction and current profile relaxation. In order to sustain heating in the multi-second pulse range, neutral beam devices must be capable of the same pulse durations. By upgrading the beam collimator… more
Date: October 1981
Creator: Doll, D. W.; McColl, D. B. & Pipkins, J. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Doublet III beamline: as-built

Description: In order to fully exploit Doublet III capabilities and to study new plasma physics regimes, a Neutral Beam Injector System has been constructed. Initially, a two beamline system will supply 7 MW of heat to the plasma. The system is currently being expanded to inject approx. 20 MW of power (6 beamlines). Each beamline is equipped with two Lawrence Berkeley Laboratory type rectangular ion sources with 10 cm x 40 cm extraction grids. These sources will accelerate hydrogen ions to 80 keV, with extr… more
Date: March 1, 1980
Creator: Harder, C.R.; Holland, M.M.; Parker, J.W.; Gunn, J. & Resnick, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Weak turbulence theory of ion temperature gradient modes for inverted density plasmas

Description: Typical profiles measured in H-mode ( high confinement'') discharges from tokamaks such as JET and DIII-D suggest that the ion temperature gradient instability threshold parameter {eta}{sub i} ({equivalent to}dlnT{sub i}/dlnn{sub i}) could be negative in many cases. Previous linear theoretical calculations have established the onset conditions for these negative {eta}{sub i}-modes and the fact that their growth rate is much smaller than their real frequency over a wide range of negative {eta}{s… more
Date: September 1, 1989
Creator: Hahm, T.S. & Tang, W.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermal and structural analysis of the LBL 10 x 40 cm long pulse accelerator and the 12 x 48 cm common long pulse accelerator for TFTR, doublet III-D, and MFTF-B

Description: Stress and deflection of the grid rails of the existing, Lawrence Berkeley Laboratory (LBL) designed, 10 x 40 cm Long Pulse (neutral beam) Accelerator (40LPA) and the expanded 12 x 48 cm version, Common Long Pulse Source (CLPS), have been computed for a series of assumed heat load distributions. The combined stress from self-constraint of thermal expansion and rail holder reaction forces has been calculated. A simplification of the gradient grid rail holder was analyzed and was found to work as… more
Date: November 1, 1985
Creator: Wells, R.P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Axisymmetric scrape-off plasma transport

Description: The two-dimensional flow of a collision dominated hydrogen scrape-off plasma in an axisymmetric tokamak is examined. This flow is described by a set of equations which contain the dominant terms in a maximal ordering appropriate to high density experimental divertors and reactor scrape-off plasmas. Comparison of the theory to estimates of scrape-off parameters in the Doublet III expanded boundary plasmas suggests that analysis of classical and neoclassical processes alone may be sufficient to p… more
Date: May 1, 1983
Creator: Singer, C. E. & Langer, W. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Resonant-cavity ICRF coupler for large tokamaks

Description: A new resonant-cavity ICRF coupler is proposed for large tokamaks. The design features a novel resonant cavity, an rf magnetic-field orientation that effectively radiates fast Alfven waves, matching to 40 ..cap omega.. transmission lines, and an electric-field orientation so that the strongest rf electric fields are orthogonal to the main toroidal magnetic field thereby benefitting from magnetic insulation. As a result, the power handling capability is excellent. For the case of the Big-Dee Dou… more
Date: April 1, 1983
Creator: Perkins, F.W. & Kluge, R.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Doublet III neutral beam test tank design

Description: A tank has been designed for testing the Doublet III Neutral Beam Injector which simulates the entrance and pressure conditions of the Doublet III vacuum vessel. The cylindrical shape vacuum vessel is the same size as the neutral beam injector vessel. Contained inside are a cylindrical cryopanel, a V-shaped calorimeter, and a retractable sample-holding device to be used for beam armor proof testing. The cryopanel has 4.2 m of surface for pumping the hydrogen load created by beam impingement on … more
Date: March 1, 1980
Creator: Doll, D.W.; Kamperschroer, J.H. & Bailey, E.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Preliminary results of noncircular plasma experiments in Doublet III

Description: Preliminary results of noncircular plasma experiments in Doublet III are reported. Shaping and discharge characteristics in doublet plasmas with high-Z limiters are described. Electron energy confinement and maximum plasma density are in agreement with standard circular tokamak empirical scaling laws. Chromium and molybdenum appear to be the dominant high-Z contaminants while carbon appears to dominate low-Z contaminants. High-Z impurity radiation does not appear to dominate the central power b… more
Date: February 1, 1980
Creator: Ohkawa, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen