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Heating and current drive on NSTX and HHFW experiments on CDX-U

Description: The NSTX (National Spherical Torus Experiment) device to be built at Princeton is a low-aspect-ratio toroidal device that has the achievement of high toroidal beta ({approximately} 45%) and noninductive operation as two of its main research goals. To achieve these goals, significant auxiliary-heating and current-drive systems are required. Present plans include ECH (electron cyclotron heating) for preionized and start-up assist, HHFW (high harmonic fast wave) for heating and current drive, and,… more
Date: July 1, 1998
Creator: Wilson, J. R.; Hosea, J. & Grisham, L.
Partner: UNT Libraries Government Documents Department
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Orbit width scaling of TAE instability growth rate

Description: The growth rate of Toroidal Alfven Eigenmodes (TAE) driven unstable by resonant coupling of energetic charged particles is evaluated in the ballooning limit over a wide range of parameters. All damping effects are ignored. Variations in orbit width, aspect ratio, and the ratio of alfven velocity to energetic particle birth velocity, are explored. The relative contribution of passing and trapped particles, and finite Larmor radius effects, are also examined. The phase space location of resonant … more
Date: July 1, 1995
Creator: Wong, H.V.; Berk, H.L. & Breizman, B.N.
Partner: UNT Libraries Government Documents Department
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Characterization of disruptions in the Microwave Tokamak Experiment, MTX

Description: The Microwave Tokamak Experiment (MTX) has a substantial number of fast diagnostics, especially for electrons, as part of its mission for pulsed, high-power electron cyclotron heating. As part of its contribution to ITER R D, these diagnostics are being used to characterize disruptions in MTX. This report is the first of two, with the second planned for submittal in September 1990, at the end of the ITER conceptual design activity. Here, we analyze the characteristics of disruptions during norm… more
Date: March 30, 1990
Creator: Hooper, E. B. & Makowski, M. A.
Partner: UNT Libraries Government Documents Department
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Linear oscillations in general magnetically confined plasmas. ARMOR RADIUS; MAGNETIC FIELD CONFIGURATIONS; WAVE PROPAGATION

Description: A systematic formalism for investigating linear electromagnetic perturbations in general magnetic field configurations is developed. The formalism employs the small adiabaticity parameter rho/L/sub 0/ and is valid for arbitrary frequencies. Here, rho and L/sub 0/ are, respectively, the Larmor radius and equilibrium scale length. Effects associated with plasma and magnetic field inhomogeneities as well as finite Larmor radii are contained. The specific case of axisymmetric tokamaks is then consi… more
Date: April 1, 1982
Creator: Chen, L. & Tsai, S.T.
Partner: UNT Libraries Government Documents Department
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Optimization of transport in stellarators

Description: Here we relate two stellarator transport optimization schemes to single particle orbits. We also show that reducing transport in the 1/..nu.. regime reduces transport over a much broader range of collisionality. 6 refs., 2 figs.
Date: January 1, 1989
Creator: Hedrick, C.L.; Beasley, C.O. & Van Rij, W.I.
Partner: UNT Libraries Government Documents Department
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Effect of the aspect ratio on the stability limits of TJ-II-like stellarators

Description: The four-field-period device TJ-II has a major radius of 1.5 m and an average plasma radius of 0.10--0.25 m, with a typical plasma aspect ratio A{sub P} of 10. In the infinite aspect ratio, helically symmetric limit, the region of the stability to low-n modes has been shown to extend to average betas of at least 40%, for a relatively highly indented plasma. It is possible to approximate the helically symmetric limit from the actual TJ-II parameters increasing the number of toroidal periods N{su… more
Date: January 1, 1991
Creator: Varias, A.; Alvarez, A.; Fraguas, A. L.; Alejaldre, C.; Dominguez, N.; Carreras, B. A. et al.
Partner: UNT Libraries Government Documents Department
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Fusion energy

Description: The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Age… more
Date: September 1, 1990
Partner: UNT Libraries Government Documents Department
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Logical and physical database design within a full-text environment

Description: This paper describes the problems and solutions encountered in the design of logical and physical data bases within a full-text environment. A full-text environment can be defined as data bases that store both citation information as well as actual document text. The problems/solutions encountered were a result of the necessity to integrate distinct physical data bases into a single logical data base without the assistance of a Data Base Management System that is capable of physical data base i… more
Date: January 1, 1985
Creator: Michelsen, C.D. & Shafer, D.F.
Partner: UNT Libraries Government Documents Department
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Stellarator approach to toroidal plasma confinement

Description: An overview is presented of the development and current status of the stellarator approach to controlled thermonuclear confinement. Recent experimental, theoretical, and systems developments have made this concept a viable option for the evolution of the toroidal confinement program. Some experimental study of specific problems associated with departure from two-dimensional symmetry must be undertaken before the full advantages and opportunities of steady-state, net-current-free operation can b… more
Date: December 1, 1981
Creator: Johnson, J. L.
Partner: UNT Libraries Government Documents Department
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Comprehensive numerical modelling of tokamaks

Description: We outline a plan for the development of a comprehensive numerical model of tokamaks. The model would consist of a suite of independent, communicating packages describing the various aspects of tokamak performance (core and edge transport coefficients and profiles, heating, fueling, magnetic configuration, etc.) as well as extensive diagnostics. These codes, which may run on different computers, would be flexibly linked by a user-friendly shell which would allow run-time specification of packag… more
Date: January 3, 1991
Creator: Cohen, R.H.; Cohen, B.I. & Dubois, P.F.
Partner: UNT Libraries Government Documents Department
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Recent progress in stellarator reactor conceptual design

Description: The Stellarator/Torsatron/Heliotron (S/T/H) class of toroidal magnetic fusion reactor designs continues to offer a distinct and in several ways superior approach to eventual commercial competitiveness. Although no major, integrated conceptual reactor design activity is presently underway, a number of international research efforts suggest avenues for the substantial improvement of the S/T/H reactor embodiment, which derive from recent experimental and theoretical progress and are responsive to … more
Date: January 1, 1985
Creator: Miller, R. L.
Partner: UNT Libraries Government Documents Department
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New directions for the TEAM workshops

Description: I consider it a great honor to be invited to speak at this, the first TEAM Workshop to take place in China. This is my first visit to China, and I am struck by the beauty of the country, by the kindness of the people I have met here, and by the rapid progress being made in every area. The topic I have chosen for this talk is New Directions for TEAM.'' But it has been said that in order to know where you are going, you must first know where you are and where you have been. So I will talk about t… more
Date: January 1, 1992
Creator: Turner, L. R.
Partner: UNT Libraries Government Documents Department
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Recent progress on the HESS (High Explosive Spheromak Source) experiment

Description: The new objective of the Los Alamos spheromak program is to assess the use of magnetized plasmas as an energy transfer medium to accelerate material objects to hyper-velocities ({approx gt} 20 km/s). In meeting this objective, we are committed to the subordinate goals of creating high field, long-lived spheromak discharges, examining the technical feasibility of employing High Explosives (HE) to compress seed spheromaks, and investigate the technical requirements involved in forming spheromaks … more
Date: January 1, 1989
Creator: Mayo, R. M.; Barnes, D. C.; Freeman, B.; Henins, I.; Jarboe, T. R.; Platts, D. (Los Alamos National Lab., NM (USA) et al.
Partner: UNT Libraries Government Documents Department
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Stellarator program

Description: The worldwide development of stellarator research is reviewed briefly and informally.
Date: August 1, 1981
Creator: Johnson, J. L.; Grieger, G.; Lees, D. J.; Rabinovich, M. S.; Shohet, J. L. & Uo, K.
Partner: UNT Libraries Government Documents Department
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Ideal low-n and Mercier mode stability boundaries for /ell/ = 2 torsatrons

Description: We studied the relationship between the stability properties of ideal low-n-internal modes and the three-dimensional (3-D) ideal Mercier criterion for /ell/ = 2 torsatron configurations. For the low-n stability studies, we used the stellarator expansion as implemented in the FAR code. The 3-D Mercier criterion was applied to equilibria calculated with the VMEC code. We found that low-n modes with singular surfaces lying in a Mercier region are, in general, unstable and the critical beta given b… more
Date: January 1, 1989
Creator: Dominguez, N.
Partner: UNT Libraries Government Documents Department
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Multiple mode model of tokamak transport

Description: Theoretical models for radical transport of energy and particles in tokamaks due to drift waves, rippling modes, and resistive ballooning modes have been combined in a predictive transport code. The resulting unified model has been used to simulate low confinement mode (L-mode) energy confinement scalings. Dependence of global energy confinement on electron density for the resulting model is also described. 26 refs., 1 fig., 2 tabs.
Date: July 1, 1989
Creator: Singer, C. E.; Ghanem, E. S.; Bateman, G. & Stotler, D. P.
Partner: UNT Libraries Government Documents Department
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Status of tokamak research

Description: An overall review of the tokamak program is given with particular emphasis upon developments over the past five years in the theoretical and experimental elements of the program. A summary of the key operating parameters for the principal tokamaks throughout the world is given. Also discussed are key issues in plasma confinement, plasma heating, and tokamak design. (MOW)
Date: October 1, 1979
Creator: Rawls, J.M. (ed.)
Partner: UNT Libraries Government Documents Department
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Plasma confinement theory and transport simulation

Description: The objectives continue to be: (1) to advance the transport studies of tokamaks, including development and maintenance of the Magnetic Fusion Energy Database, and (2) to provide theoretical interpretation, modeling and equilibrium and stability for TEXT-Upgrade. Recent publications and reports, and conference presentations of the Fusion Research Center theory group are listed.
Date: February 1, 1993
Creator: Ross, D.W.
Partner: UNT Libraries Government Documents Department
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