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Effects of Large Area Liquid Lithium Limiters on Spherical Torus Plasmas

Description: Use of a large-area liquid lithium surface as a first wall has significantly improved the plasma performance in the Current Drive Experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory. Previous CDX-U experiments with a partially-covered toroidal lithium limiter tray have shown a decrease in impurities and the recycling of hydrogenic species. Improvements in loading techniques have permitted nearly full coverage of the tray surface with liquid lithium. Under these conditions, the… more
Date: June 3, 2004
Creator: Kaita, R.; Majeski, R.; Boaz, M.; Efthimion, P.; Gettelfinger, G.; Gray, T. et al.
Partner: UNT Libraries Government Documents Department
open access

A Novel Demountable TF Joint Design for Low Aspect Ratio Spherical Torus Tokamaks

Description: A novel shaped design for the radial conductors and demountable electrical joints connecting inner and outer legs of copper TF system conductors in low aspect ratio tokamaks is described and analysis results are presented. Specially shaped designs can optimize profiles of electrical current density, magnetic force, heating, and mechanical stress.
Date: May 29, 2009
Creator: Woolley, R.D.
Partner: UNT Libraries Government Documents Department
open access

National Spherical Torus Experiment (NSTX) Center Stack Upgrade

Description: The purpose of the NSTX Center Stack Upgrade project is to expand the NSTX operational space and thereby the physics basis for next-step ST facilities. The plasma aspect ratio (ratio of plasma major to minor radius) of the upgrade is increased to 1.5 from the original value of 1.26, which increases the cross sectional area of the center stack by a factor of ~ 3 and makes possible higher levels of performance and pulse duration.
Date: September 24, 2009
Creator: Neumeyer, C.; Chrzanowski, J.; Dudek, L.; Fan, H.; Hatcher, R.; Heitzenroeder, P. et al.
Partner: UNT Libraries Government Documents Department
open access

Physics Design of the National High-Power Advanced Torus eXperiment

Description: Moving beyond ITER toward a demonstration power reactor (Demo) will require the integration of stable high fusion gain in steady-state, advanced methods for dissipating very high divertor heat-fluxes, and adherence to strict limits on in-vessel tritium retention. While ITER will clearly address the issue of high fusion gain, and new and planned long-pulse experiments (EAST, JT60-SA, KSTAR, SST-1) will collectively address stable steady-state high-performance operation, none of these devices wil… more
Date: July 2, 2007
Creator: Menard, J; Goldston, R; Fu, G; Gorelenkov, N; Kaye, S; Kramer, G et al.
Partner: UNT Libraries Government Documents Department
open access

Analysis of NSTX TF Joint Voltage Measurements

Description: This report presents findings of analyses of recorded current and voltage data associated with 72 electrical joints operating at high current and high mechanical stress. The analysis goal was to characterize the mechanical behavior of each joint and thus evaluate its mechanical supports. The joints are part of the toroidal field (TF) magnet system of the National Spherical Torus Experiment (NSTX) pulsed plasma device operating at the Princeton Plasma Physics Laboratory (PPPL). Since there is no… more
Date: October 7, 2005
Creator: Woolley, R.
Partner: UNT Libraries Government Documents Department
open access

Development of an Extreme Environment Materials Research Facility at Princeton

Description: The need for a fundamental understanding of material response to a neutron and/or high heat flux environment can yield development of improved materials and operations with existing materials. Such understanding has numerous applications in fields such as nuclear power (for the current fleet and future fission and fusion reactors), aerospace, and other research fields (e.g., high-intensity proton accelerator facilities for high energy physics research). A proposal has been advanced to develop a… more
Date: November 17, 2010
Creator: Cohen, A. B.; Tully, C. G.; Austin, R.; Calaprice, F.; McDonald, K.; Ascione, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Testing of Liquid Lithium Limiters in CDX-U

Description: Part of the development of liquid metals as a first wall or divertor for reactor applications must involve the investigation of plasma-liquid metal interactions in a functioning tokamak. Most of the interest in liquid-metal walls has focused on lithium. Experiments with lithium limiters have now been conducted in the Current Drive Experiment-Upgrade (CDX-U) device at the Princeton Plasma Physics Laboratory. Initial experiments used a liquid-lithium rail limiter (L3) built by the University of C… more
Date: July 30, 2004
Creator: Majeski, R.; Kaita, R.; Boaz, M.; Efthimion, P.; Gray, T.; Jones, B. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of Large Area Liquid Lithium Limiters on Spherical Torus Plasmas

Description: Use of a large-area liquid lithium surface as a first wall has significantly improved the plasma performance in the Current Drive Experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory. Previous CDX-U experiments with a partially-covered toroidal lithium limiter tray have shown a decrease in impurities and the recycling of hydrogenic species. Improvements in loading techniques have permitted nearly full coverage of the tray surface with liquid lithium. Under these conditions, the… more
Date: June 7, 2004
Creator: Kaita, R.; Majeski, R.; Boaz, M.; Efthimion, P.; Gettelfinger, G.; Gray, T. et al.
Partner: UNT Libraries Government Documents Department
open access

Status and Plans for the National Spherical Torus Experimental Research Facility

Description: An overview of the research capabilities and the future plans on the MA-class National Spherical Torus Experiment (NSTX) at Princeton is presented. NSTX research is exploring the scientific benefits of modifying the field line structure from that in more conventional aspect ratio devices, such as the tokamak. The relevant scientific issues pursued on NSTX include energy confinement, MHD stability at high beta, non-inductive sustainment, solenoid-free start-up, and power and particle handling. I… more
Date: July 27, 2005
Creator: Columbia University
Partner: UNT Libraries Government Documents Department
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Spherical Torus Plasma Interactions with Large-area Liquid Lithium Surfaces in CDX-U

Description: The Current Drive Experiment-Upgrade (CDX-U) device at the Princeton Plasma Physics Laboratory (PPPL) is a spherical torus (ST) dedicated to the exploration of liquid lithium as a potential solution to reactor first-wall problems such as heat load and erosion, neutron damage and activation, and tritium inventory and breeding. Initial lithium limiter experiments were conducted with a toroidally-local liquid lithium rail limiter (L3) from the University of California at San Diego. Spectroscopic m… more
Date: January 18, 2002
Creator: Kaita, R.; Majeski, R.; Boaz, M.; Efthimion, P.; Jones, B.; Hoffman, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Spherical Torus Center Stack Design

Description: The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device.
Date: January 18, 2002
Creator: Neumeyer, C.; Heitzenroeder, P.; Kessel, C.; Ono, M.; Peng, M.; Schmidt, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Modeling of Spherical Torus Plasmas for Liquid Lithium Wall Experiments

Description: Liquid metal walls have the potential to solve first-wall problems for fusion reactors, such as heat load and erosion of dry walls, neutron damage and activation, and tritium inventory and breeding. In the near term, such walls can serve as the basis for schemes to stabilize magnetohydrodynamic (MHD) modes. Furthermore, the low recycling characteristics of lithium walls can be used for particle control. Liquid lithium experiments have already begun in the Current Drive eXperiment-Upgrade (CDX-U… more
Date: January 29, 2002
Creator: Kaita, R.; Jardin, S.; Jones, B.; Kessel, C.; Majeski, R.; Spaleta, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Next Step Spherical Torus Design Studies

Description: Studies are underway to identify and characterize a design point for a Next Step Spherical Torus (NSST) experiment. This would be a ''Proof of Performance'' device which would follow and build upon the successes of the National Spherical Torus Experiment (NSTX) a ''Proof of Principle'' device which has operated at PPPL since 1999. With the Decontamination and Decommissioning (D&D) of the Tokamak Fusion Test Reactor (TFTR) nearly completed, the TFTR test cell and facility will soon be availa… more
Date: November 8, 2002
Creator: Neumeyer, C.; Heitzenroeder, P.; Kessel, C.; Ono, M.; Peng, M.; Schmidt, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Next-Step Spherical Torus Experiment and Spherical Torus Strategy in the Fusion Energy Development Path

Description: A spherical torus (ST) fusion energy development path which is complementary to proposed tokamak burning plasma experiments such as ITER is described. The ST strategy focuses on a compact Component Test Facility (CTF) and higher performance advanced regimes leading to more attractive DEMO and Power Plant scale reactors. To provide the physics basis for the CTF an intermediate step needs to be taken which we refer to as the ''Next Step Spherical Torus'' (NSST) device and examine in some detail h… more
Date: October 27, 2003
Creator: Ono, M.; Peng, M.; Kessel, C.; Neumeyer, C.; Schmidt, J.; Chrzanowski, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Liquid Lithium Limiter Effects on Tokamak Plasmas and Plasma-Liquid Surface Interactions

Description: We present results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. The… more
Date: October 15, 2002
Creator: Kaita, R.; Majeski, R.; Doerner, R.; Antar, G.; Baldwin, M.; Conn, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Method and apparatus for steady-state magnetic measurement of poloidal magnetic field near a tokamak plasma

Description: A method and apparatus for the steady-state measurement of poloidal magnetic field near a tokamak plasma, where the tokamak is configured with respect to a cylindrical coordinate system having z, phi (toroidal), and r axes. The method is based on combining the two magnetic field principles of induction and torque. The apparatus includes a rotor assembly having a pair of inductive magnetic field pickup coils which are concentrically mounted, orthogonally oriented in the r and z directions, and c… more
Date: December 31, 1996
Creator: Woolley, R.D.
Partner: UNT Libraries Government Documents Department
open access

Long Pulse Fusion Physics Experiments without Superconducting Electromagnets

Description: Long-pulse fusion physics experiments can be performed economically via resistive electromagnets designed for thermally steady-state operation. Possible fusion experiments using resistive electromagnets include long-pulse ignition with deuterium-tritium fuel. Long-pulse resistive electromagnets are alternatives to today's delicate and costly superconductors. At any rate, superconducting technology is now evolving independent of fusion, so near-term superconducting experience may not ultimately … more
Date: August 19, 1998
Creator: Woolley, R.D.
Partner: UNT Libraries Government Documents Department
open access

Improved Magnetic Fusion Energy Economics via Massive Resistive Electromagnets

Description: Abandoning superconductors for magnetic fusion reactors and instead using resistive magnet designs based on cheap copper or aluminum conductor material operating at "room temperature" (300 K) can reduce the capital cost per unit fusion power and simplify plant operations. By increasing unit size well beyond that of present magnetic fusion energy conceptual designs using superconducting electromagnets, the recirculating power fraction needed to operate resistive electromagnets can be made as clo… more
Date: August 19, 1998
Creator: Woolley, R.D.
Partner: UNT Libraries Government Documents Department
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