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Comparative analysis of a fusion reactor blanket in cylindrical and toroidal geometry using Monte Carlo

Description: Differences in neutron fluxes and nuclear reaction rates in a noncircular fusion reactor blanket when analyzed in cylindrical and toroidal geometry are studied using Monte Carlo. The investigation consists of three phases--a one-dimensional calculation using a circular approximation to a hexagonal shaped blanket; a two-dimensional calculation of a hexagonal blanket in an infinite cylinder; and a three-dimensional calculation of the blanket in tori of aspect ratios 3 and 5. The total blanket rea… more
Date: March 1, 1976
Creator: Chapin, D. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MHD stability properties of bean-shaped tokamaks

Description: A study of the MHD stability properties of bean-shaped tokamak plasmas is presented. For ballooning modes, while increased indentation gives larger ..beta.. stable configurations, the existence and accessibility of the second stable region is sensitive to the pressure and safety factor profiles. The second stable region appears at lower ..beta.. values for large aspect ratio and moderately high q-values. Finite-Larmor-radius (FLR) kinetic effects can significantly improve the stability properti… more
Date: March 1, 1984
Creator: Grimm, R. C.; Chance, M. S.; Todd, A. M. M.; Manickam, J.; Okabayashi, M.; Tang, W. M. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Equilibrium toroidal current in a tokamak driven by phase-space inhomogeneity in the banana regime

Description: In the hot core region of a tokamak plasma column, the radial guiding center motion of the charged particles is affected by the existence of the magnetic axis. Identical particles with opposite signs of toroidal velocity drift in opposite radial directions. But, the magnetic axis acts like a rigid wall and imposes a boundary condition on the radial guiding center motions, causing asymmetrical radial particle motions between toroidally oppositely flowing particles, or between radially oppositely… more
Date: March 1, 1989
Creator: Chang, C. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fusion-reactor aspects of the compact torus

Description: This paper summarizes several studies of fusion reactors based on the compact torus (CT). A wide variety of reactor configurations can be projected within present understanding of the possible types of CT and their macroscopic stability and confinement properties. Three types of CT are considered here, the field-reversed-configuration having B/sub Toroidal/ = 0, the Spheromak with B/sub T/ not equal to 0, and CT's formed with particle rings. For each type, either fixed or moving-ring possibilit… more
Date: March 11, 1981
Creator: Hartman, Charles W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Summary of U.S. Compact Torus Experiments

Description: During the past several years a rapid increase has occurred in compact torus (CT) research in the United States, reflecting renewed interest in this simplified reactor consequences of this configuration. This paper reviews early approaches to CT formation and results and summarizes present experimental studies. Recent experiments have demonstrated a number of macroscopic aspects of the CT, including the conditions under which a macroscopically stable CT can be formed and maintained. Scaling exp… more
Date: March 11, 1981
Creator: Hartman, Charles W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Proposal to produce large compact toroids

Description: Relatively large, hot compact toroids might be produced in the annular space between two concentric one-turn coils. With currents in the two coils flowing in the same direction, the magnetic fields on each side of the plasma are in opposite directions. As the fields are raised, the plasma ring is heated and compressed radially towards the center of the annular space. By the addition of two sets of auxiliary coils, the plasma ring can be ejected out one end of the two-coil system into a long axi… more
Date: March 1, 1981
Creator: Phillips, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Proceedings of the third symposium on the physics and technology of compact toroids in the magnetic fusion energy program

Description: This document contains papers contributed by the participants of the Third Symposium on Physics and Technology of Compact Toroids in the Magnetic Fusion Energy Program. Subjects include reactor aspects of compact toroids, energetic particle rings, spheromak configurations (a mixture of toroidal and poloidal fields), and field-reversed configurations (FRC's that contain purely poloidal field).
Date: March 1, 1981
Creator: Siemon, R.E. (comp.)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Compact-Toroid fusion reactor based on the field-reversed theta pinch

Description: Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CTOR) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor envi… more
Date: March 1, 1981
Creator: Hagenson, R. L. & Krakowski, R. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of toroidicity on resistive tearing modes

Description: A reduced set of resistive MHD equations is solved numerically in three dimensions to study the stability of tokamak plasmas. Toroidal effects are included self-consistently to leading and next order in inverse aspect ratio, epsilon. The equations satisfy an energy integral. In addition, the momentum equation yields the Grad-Shafranov equation correct to all orders in epsilon. Low beta plasma are studied using several different q-profiles. In all cases, the linear growth rates are reduced by fi… more
Date: March 1, 1983
Creator: Izzo, R.; Monticello, D. A.; Manickam, J.; Strauss, H. R.; Grimm, R. & McGuire, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Confinement studies of ohmically heated plasmas in TFTR

Description: Systematic scans of density in large deuterium plasmas (a = 0.83 m) at several values of plasma current and toroidal magnetic field strength indicate that the total energy confinement time, tau/sub E/, is proportional to the line-average density anti n/sub e/ and the limiter q. Confinement times of approx. 0.3 s have been observed for anti n/sub e/ = 2.8 x 10/sup 19/ m/sup -3/. Plasma size scaling experiments with plasmas of minor radii a = 0.83, 0.69, 0.55, and 0.41 m at constant limiter q rev… more
Date: March 1, 1985
Creator: Efthimion, P. C.; Bretz, N. L.; Bell, M. G.; Bitter, M.; Blanchard, W. R.; Boody, F. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Pressure limits of an axisymmetric torus

Description: In order to clarify the pressure limit of a toroidal plasma equilibrium in a three-dimensional geometry, an azimuthally symmetric toroidal plasma was considered. In a tokamak-like plasma, the net toroidal current is necessary for a finite ..beta.. plasma equilibrium. If external conductors are used to provide the rotational transform, iota, the plasma pressure is limited to ..beta.. = (iota/2..pi..)/sup 2//2A, where A is the aspect ratio.
Date: March 1, 1986
Creator: Yoshikawa, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An analytic solution of high. beta. equilibrium in a large aspect ratio tokamak

Description: An analytic solution of the high {beta} ({epsilon}{bar {beta}}{sub p} {approximately} {beta}q{sup 2}/{epsilon} {much gt} 1) equilibrium of a large aspect ratio tokamak is presented. Two arbitrary flux functions, the pressure profile p({psi}) and the safety factor profile q({psi}), specify the equilibrium. The solution splits into two asymptotic regions: the core region where {psi} is a function of the major radius alone and a narrow boundary layer region adjoining the conducting wall. The solut… more
Date: March 1, 1991
Creator: Cowley, S.C.; Kaw, P.K.; Kelly, R.S. & Kulsrud, R.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Scoping and sensitivity analyses for the Demonstration Tokamak Hybrid Reactor (DTHR)

Description: The results of an extensive set of parametric studies are presented which provide analytical data of the effects of various tokamak parameters on the performance and cost of the DTHR (Demonstration Tokamak Hybrid Reactor). The studies were centered on a point design which is described in detail. Variations in the device size, neutron wall loading, and plasma aspect ratio are presented, and the effects on direct hardware costs, fissile fuel production (breeding), fusion power production, electri… more
Date: March 1, 1979
Creator: Sink, D. A. & Gibson, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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OCLATOR II (One Coil Low Aspect Toroidal Reactor)

Description: Following the general description of OCLATOR (I), more thoughts are presented here. It suggests that the blanket may not be changed for the plant lifetime. Also miniaturization of OCLATOR is discussed, especially if the ripple turbulence could be improved upon the presently set limit which applies to a large number of ripples.
Date: March 1, 1980
Creator: Yoshikawa, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Receiver for solar-energy collector having improved aperture aspect

Description: A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the receiver as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide a receiver having a desired aperture aspect.
Date: March 13, 1981
Creator: McIntire, W.R.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Planarization of High Aspect Ratio P-I-N Diode Pillar Arrays for Blanket Electrical Contacts

Description: Two planarization techniques for high aspect ratio three dimensional pillar structured P-I-N diodes have been developed in order to enable a continuous coating of metal on the top of the structures. The first technique allows for coating of structures with topography through the use of a planarizing photoresist followed by RIE etch back to expose the tops of the pillar structure. The second technique also utilizes photoresist, but instead allows for planarization of a structure in which the pil… more
Date: March 5, 2009
Creator: Voss, L F; Shao, Q; Reinhardt, C E; Graff, R T; Conway, A M; Nikolic, R J et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Confinement and Local Transport in the National Spherical Torus Experiment NSTX

Description: NSTX operates at low aspect ratio (R/a~1.3) and high beta (up to 40%), allowing tests of global confinement and local transport properties that have been established from higher aspect ratio devices. NSTX plasmas are heated by up to 7 MW of deuterium neutral beams with preferential electron heating as expected for ITER. Confinement scaling studies indicate a strong ΒΤ dependence, with a current dependence that is weaker than that observed at higher aspect ratio. Dimensionless scaling experiment… more
Date: March 15, 2007
Creator: Kaye, S. M.; Stutman, D.; Tritz, K.; Yuh, H.; Bell, M. G.; Bell, R. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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SYNTHESIS AND CHARACTERIZATION OF CARBON AEROGEL NANOCOMPOSITES CONTAINING DOUBLE-WALLED CARBON NANOTUBES

Description: Carbon aerogels (CAs) are novel mesoporous materials with applications such as electrode materials for super capacitors and rechargeable batteries, adsorbents and advanced catalyst supports. To expand the potential application for these unique materials, recent efforts have focused on the design of CA composites with the goal of modifying the structure, conductivity or catalytic activity of the aerogel. Carbon nanotubes (CNTs) possess a number of intrinsic properties that make them promising ma… more
Date: March 11, 2008
Creator: Worsley, M A; Satcher, J H & Baumann, T F
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Integration of Ion Implantation with Scanning ProbeAlignment

Description: We describe a scanning probe instrument which integrates ion beams with imaging and alignment functions of a piezo resistive scanning probe in high vacuum. Energetic ions (1 to a few hundred keV) are transported through holes in scanning probe tips [1]. Holes and imaging tips are formed by Focused Ion Beam (FIB) drilling and ion beam assisted thin film deposition. Transport of single ions can be monitored through detection of secondary electrons from highly charged dopant ions (e. g., Bi{sup 45… more
Date: March 1, 2005
Creator: Persaud, A.; Rangelow, I. W. & Schenkel, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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e-/e+ Accelerating Structure with Cyclic Variation of Azimuth Asymmetry

Description: A classical electron/positron accelerating structure is a disk-loaded cylindrical waveguide. The accelerator structure here has azimuth symmetry. The proposed structure contains a disk-loaded cylindrical waveguide where there is a periodical change of RF-field vs. azimuth. The modulation deforms the rf-field in such a manner that the accelerated particles undergo transverse focusing forces. The new class of accelerator structures covers the initial part of e+/e- linacs where a bunch is not rigi… more
Date: March 5, 2007
Creator: Krasnykh, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Advanced Crystal Growth Technology

Description: Although the fundamental mechanism of crystal growth has received and continues to receive deserved attention as a research activity, similar research efforts addressing the need for advanced materials and processing technology required to grow future high quality crystals has been sorely lacking. The purpose of this research effort is to develop advanced rapid growth processing technologies and materials suitable for providing the quality of products needed for advanced laser and photonics app… more
Date: March 1, 2005
Creator: Land, T A & Hawley-Fedder, R A
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Numerical study of the MHD spectrum in tokamaks with a noncircular cross section

Description: The behavior of a class of exact tokamak equilibria is investigated in the context of ideal magnetohydrodynamics. The equilibrium solution allows for a general plasma cross section shape, restricted to systems with essentially flat toroidal current profiles. The spectrum of the eigenmodes is evaluated by extremizing the Lagrangian using a Galerkin procedure. The different branches of the spectrum are appropriately represented by expanding the eigenfunctions in terms of the eigenfunctions of the… more
Date: March 1, 1976
Creator: Kerner, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Axial Stress on YBCO Coils

Description: The large aspect ratio of typical YBCO conductors makes them ideal for constructing solenoids from pancake style coils. An advantage of this method is that each subunit can be tested before assembly into the finished magnet. The fact that conductors are available in relatively short lengths is another reason for using such a fabrication technique. The principal drawback is the large number of joints required to connect the coils together. When very high field solenoids such as those contemplate… more
Date: March 28, 2011
Creator: Sampson, W.; Anerella, M.; Cozzolino, J.P.; Gupta, R.C.; Shiroyanagi, Y. & Evangelou, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

NSLS-II X-Ray Diagnostics Development

Description: NSLS-II x-ray diagnostics will provide continuous online data of electron beam dimensions, which will be used to derive electron beam emittance and energy spread. It will also provide information of electron beam tilt for coupling evaluation. X-ray diagnostics will be based on imaging of bending magnet and three-pole wiggler synchrotron radiation sources. Diagnostics from three-pole wiggler source will be used to derive particles energy spread. Beta and dispersion functions will have to be eval… more
Date: March 28, 2011
Creator: Ilinski, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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