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Status of Oak Ridge National Laboratory fusion activities

Description: This review covers the following research being carried out at ORNL: (1) confinement experiments such as ATF, EBT, and STX, (2) theory, (3) atomic physics, (4) shielding, (5) technology developments on superconducting magnets, pellet injection, rf plasma heating, and materials, and (6) fusion engineering design center. (MOW)
Date: January 1, 1985
Creator: Rosenthal, M.W.
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Partner: UNT Libraries Government Documents Department
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Gorter-Mellink pulsed-source problem in cylindrical and spherical geometry

Description: An exact solution to the Gorter-Mellink pulsed-source problem is known in plane geometry. According to this solution, the central temperature falls as t{sup {minus}3/2}, where t is the elapsed time after an instantaneous, plane pulse. No such exact solutions are known to the pulsed-source problem in cylindrical and spherical geometry. But in cylindrical geometry, it can be shown that if the initial condition is an instantaneous temperature rise {Delta}T inside a cylinder of radius R, the centra… more
Date: January 1, 1991
Creator: Dresner, L.
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Partner: UNT Libraries Government Documents Department
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Spherical torus: an approach to compact fusion at low field. Initial ignition assessments

Description: Initial assessments of ignition devices based on the spherical torus concept suggest that an ignition spherical torus (IST) can be highly cost-effective and exceptionally small in unit size. Assuming advanced methods of current drive and confinement and beta scalings with plasma current, a D-T IST with a toroidal field of 2 to 3 T is estimated to have a major radius ranging from 1 m to 1.6 m, and a fusion power less than 60 MW. For the nominal IST (at 2 T and 1.6 m), the direct cost of the nucl… more
Date: January 1, 1985
Creator: Peng, Y. K. M.; Strickler, D. J.; Borowski, S. K.; Hamilton, W. R.; Reid, R. L.; Haines, J. R. et al.
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Partner: UNT Libraries Government Documents Department
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Compact DT fusion spherical tori at modest fields

Description: A spherical torus is obtained by retaining only the indispensable components on the inboard side of a tokamak plasma, such as a cooled, normal conductor that carries current to produce a toroidal magnetic field. The resulting device features an exceptionally small aspect ratio (typically 2-to-1 elongation), and ramp-up and maintenance of the plasma current primarily by noninductive means. The tokamak plasma takes on the spherical shape with a modest hole through the center, suggesting the name … more
Date: January 1, 1985
Creator: Peng, Y. K. M.
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Partner: UNT Libraries Government Documents Department
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An ultra-high-vacuum multiple grating chamber and scan drive with improved grating change

Description: We describe a new grating chamber and scan drive which has been designed, built, and tested by Physical Sciences Laboratory of the University of Wisconsin for the new high flux, high-resolution spectroscopy branch line of the TOK hybrid wiggler/undulator on the NSLS VUV ring. The chamber will contain spherical gratings to be used in the Spherical Grating Monochromator (SGM) configuration introduced by Chen and Sette. The grating chamber houses five 180 mm {times} 35 mm {times} 30 mm gratings ca… more
Date: January 1, 1989
Creator: Hulbert, S. L.; Holly, D. J.; Middleton, F. H. & Wallace, D. J.
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Partner: UNT Libraries Government Documents Department
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Compact DT fusion spherical tori at modest field

Description: A spherical torus is obtained by retaining only the indispensable components on the inboard side of a tokamak plasma. It features an exceptionally small aspect ratio (around 1.5), a naturally elongated, D-shaped plasma cross section (2 to 1 elongation), and ramp-up and maintenance of the plasma current primarily by advanced methods. It takes on the spherical shape with a modest hole through the center, suggesting the name.
Date: January 1, 1985
Creator: Peng, M.; Borowski, S. K.; Dalton, G. R.; Gorker, G. E.; Hamilton, W. R.; Kunselman, M. H. et al.
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Partner: UNT Libraries Government Documents Department
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Time-resolved x-ray line emission studies of thermal transport in multiple beam uv-irradiated targets

Description: Thermal transport in spherical targets irradiated with multiple, nanosecond duration laser beams, has been a topic of much discussion recently. Different inferences on the level of thermal flux inhibition have been drawn from plasma velocity and x-ray spectroscopic diagnostics. We present new measurements of thermal transport on spherical targets made through time-resolved x-ray spectroscopic measurements of the progress of the ablation surface through thin layers of material on the surface of … more
Date: January 1, 1984
Creator: Jaanimagi, P.A.; Henke, B.L.; Delettrez, J. & Richardson, M.C.
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Partner: UNT Libraries Government Documents Department
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Instability localized at the inner surface of an imploding spherical shell

Description: It is shown that in an imploding spherical shell the surface instabilities are of two different types. The first, which occurs at the outer surfaces, is the Rayleigh-Taylor instability. The second instability occurs at the inner surface. This latter instability is not as disruptive as R-T modes, but it has three basic properties which differ considerably from those of the R-T instability: (1) it is oscillatory at early times; (2) it grows faster in the long wavelength modes; (3) it depends on t… more
Date: January 1, 1983
Creator: Han, S.J.
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Partner: UNT Libraries Government Documents Department
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CVD techniques applied to energy problems

Description: Some of the applications of chemical vapor deposition in energy related programs will be discussed, and coating parameters will be described. The coatings to be discussed were made at reduced pressures from the hydrogen reduction of metal fluorides, or metal silane and from the pyrolysis of metal carbonyls.
Date: January 1, 1981
Creator: McCreary, W.J. & Carroll, D.W.
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Partner: UNT Libraries Government Documents Department
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Beam-profile measurement on the magnetoelastic microscope

Description: A proof-of-principle magnetoelastic lens has been shown to behave much as expected. Calibration of its behavior has been achieved in a relatively simple and repeatable way. The relatively good agreement with the magnetoelastic optics model gives rise to the hope that focusing of the internal field will ultimately give rise to diffraction limited operation; that is, to about 4 ..mu..m for shear wave operation at 1.0 GHz. (MOW)
Date: January 1, 1981
Creator: Bongianni, W.L.
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Partner: UNT Libraries Government Documents Department
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Application of Pade approximants to elastic wave scattering. [Spherical void differential cross sections]

Description: Several Pade methods were used to try to accelerate the convergence of partial wave sums for scattering amplitudes. A specific test problem of longitudinal-to-longitudinal scattering from a spherical void was studied in detail. Results for this test case and the behavior of partial wave amplitudes for general cases are presented and discussed. 16 references.
Date: January 1, 1979
Creator: Gubernatis, J.E.
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Partner: UNT Libraries Government Documents Department
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Thermal conductivity of mixed beryllia/Li ceramic in sphere-pac forms

Description: Lithium containing ceramic tritium breeder materials have been envisaged to be deployed within the blanket region of a fusion reactor in several possible configurations. One of these is the sphere-pac configuration. For this configuration an important material parameter is its thermal conductivity (Ksp). It is well known that Ksp demonstrates rather complex behavior as a function of temperature, gas pressure, gas composition, particle size, and packing fraction. The inter-relationship of these … more
Date: January 1, 1986
Creator: Tam, S. W. & Johnson, C. E.
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Partner: UNT Libraries Government Documents Department
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Application of nuclear models. [1 to 40 MeV, review]

Description: The development of extensive experimental nuclear data base over the past three decades has been accompanied by parallel advancement of nuclear theory and models used to describe and interpret the measurements. This theoretical capability is important because of many nuclear data requirements that are still difficult, impractical, or even impossible to meet with present experimental techniques. Examples of such data needs are neutron cross sections for unstable fission products, which are requi… more
Date: January 1, 1979
Creator: Young, P. G.; Arthur, E. D. & Madland, D. G.
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Partner: UNT Libraries Government Documents Department
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Spherical fusion plasma-confinement field of Surmac type

Description: The concept of a Surmac confinement field that can be completely closed is presented. The internal conductor is magnetically suspended inside large corrugations of a superconducting spherical shell structure that carries the return current. Presently available superconductor technology using superfluid helium cooling allows fields above 1.5T throughout the wall region. Such a Surmac has potential for the study of advanced fuel cycles.
Date: January 1, 1981
Creator: Wipf, S.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Efficient method that precisely characterizes laser-target defects more complex than nonconcentricity

Description: An expansion of an efficient, fast Fourier technique for precisely characterizing complex laser target defects is described. The defects characterized are the traditional nonconcentricities and the more complex ellipticities and higher-order wall nonuniformities in single-layered targets. This characterization method uses experimentally derived molybdenum step-wedge data. The molybdenum steps (12.5 ..mu..m) were exposed to a 45-kV tungsten-bremsstrahlung source and were recorded on holographic … more
Date: January 1, 1981
Creator: Whitman, R.L.
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Partner: UNT Libraries Government Documents Department
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Diffraction radiation produced by a charged particle passing near or through a dielectric sphere

Description: We have derived expressions for the spectral distribution of diffraction radiation produced when a charged particle of constant velocity passes near or through a dielectric sphere of radius a. Our expressions, which are valid in the long wavelength limit ka << 1, describe the production of radiation as a function of the particle's impact parameter and energy and as a function of the dielectric property of the sphere. Our results reduce to forms similar to Rayleigh scattering of light when ka ..… more
Date: January 1, 1985
Creator: Rule, D.W. & Ritchie, R.H.
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Partner: UNT Libraries Government Documents Department
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High temperature fusion reactor design

Description: Fusion energy may have unique advantages over other systems as a source for high temperature process heat. A conceptual design of a blanket for a 7 m tokamak reactor has been developed that is capable of producing 1100/sup 0/C process heat at a pressure of approximately 10 atmospheres. The design is based on the use of a falling bed of MgO spheres as the high temperature heat transfer system. By preheating the spheres with energy taken from the low temperature tritium breeding part of the blank… more
Date: January 1, 1979
Creator: Harkness, S. D.; dePaz, J. F.; Gohar, M. Y. & Stevens, H. C.
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Partner: UNT Libraries Government Documents Department
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Central collisions in intermediate energy heavy-ion reactions. [Micro- and macroscopic theory, extended time-dependent Hartree-Fock approximation]

Description: The critical collisions in intermediate energy heavy-ion reactions are examined from both a microscopic and macroscopic viewpoint. In the microscopic description the proper tool is the extended TDHF approximation involving both the mean field and the particle collisions. To understand the underlying physics, the effect of the mean field and the effect of particle collisions are studied separately. It is found that th sudden increase in the density of the overlapping region can cause the volcano… more
Date: January 1, 1979
Creator: Wong, C.Y.
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Partner: UNT Libraries Government Documents Department
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Quarterly progress report, July-September 1982

Description: Our ability to characterize fuel shells was greatly improved this quarter by the installation of the Eikonix Image Acquisition System. Linking this system to the VAX 11/750 computer permits real-time imaging of radiographic plates. Analysis of the thermal transport experimental campaign continued. We found that the mass-ablation rate was significantly higher for spherical targets than for planar targets. The ablation rate was also greater for 0.53 ..mu..m light used in similar experiments perfo… more
Date: January 1, 1982
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation on cryogenic laser fusion targets: fabrication, characterization, and transport. Annual report, December 1, 1978-November 30, 1979

Description: The research has been directed toward fabrication, characterization, and positioning of cryogenic shell laser fusion targets, with particular emphasis on the development of a scheme which would allow for continuous fabrication, inspection, and delivery of the targets. Specifically, progress has been made in the following areas: (1) Fabrication of a uniform spherical shell of DT-condensate using a cold-wall target-freezing-cell. (2) Fabrication of a uniform spherical shell of liquid DT using a r… more
Date: January 1, 1979
Creator: Kim, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Spherical shock collapse in a non-ideal medium

Description: Non-ideal fluid motions are studied. Spherical self-similar convergence is calculated for a strong shock in an ideal medium. Group theory is used to place a symmetry condition on the adiabatic bulk modulus, B/sub s/(p,v), for which three independent scale transformations of Euler's equations are admitted. The types of non-ideal media which satisfy the bulk modulus symmetry condition include equations of state of Mie-Grusneisen type. Thus the theory applies to a wide class of materials. In parti… more
Date: January 1, 1978
Creator: Axford, R. A. & Holm, D. D.
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Partner: UNT Libraries Government Documents Department
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Numerical simulation of high-energy-electron gerated field in dielectrics of various geometries. Final report, June 1, 1979-May 15, 1980

Description: It has been observed that the exposure of dielectrics to electron beams can produce an electric field of sufficient magnitude to cause dielectric breakdown. The present investigations will be directed to calculate the electric field intensity in dielectrics under spherical and cylindrical geometries. In the spherical geometry the method of multiple images renders the full numerical calculation unnecessary, whereas in a finite length cylindrical geometry the full numerical calculation seems to b… more
Date: January 1, 1980
Creator: Yee, K.S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Solar-type protostars

Description: The formation of a 1 M/sub 0 protostar in spherical symmetry has been followed in time dependent hydrodynamics with a detailed description of the equation of state and a careful treatment of radiative transport. The comparison of the dynamic evolution with observation is made in terms of the Hertzprung-Russell diagram. It is found that the evolution following from Larson's initial condition produces quantitatively and qualitativley better agreement than that following from the initial condition… more
Date: January 1, 1980
Creator: Winkler, K.H.A. & Newman, M.J.
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Partner: UNT Libraries Government Documents Department
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