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in creator/contributor: "Baity, F. W."

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Direct electron heating by 60 MHz fast waves on DIII-D

Efficient direct electron heating by fast waves has been observed on the DIII-D tokamak. A four strap antenna with (0,{pi},0,{pi}) phasing launched up to 1.6 MW of fast wave power with {vert bar}n{sub {parallel}}{vert bar} {approx} 11. This {vert bar}n{sub {parallel}}{vert bar} is suitable for strong electron interaction in ohmic target plasmas (T{sub e} {le} 2 keV). Ion cyclotron absorption was minimized by keeping the hydrogen fraction low ({lt}3%) in deuterium discharges and by operating at … more

Date: October 1, 1991

Creator: Petty, C. C.; Pinsker, R. I.; Mayberry, M. J.; Chiu, S. C.; Luce, T. C.; Prater, R. (General Atomics, San Diego, CA (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Direct electron absorption of fast waves on the D3-D tokamak

No Description Available.

Date: June 1, 1992

Creator: Petty, C. C.; Pinsker, R. I.; Chiu, S. C.; deGrassie, J. S.; Lohr, J.; Luce, T. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radio frequency vacuum feedthroughs for high-power ICRF heating applications

Frequently, high-power pulsed ion cyclotron range of frequency experiments are limited by breakdown at the vacuum feedthrough. This paper describes the development and testing of vacuum feedthroughs to increase both reliability and capability. The ultimate goal of the program is to develop a continuous-wave feedthrough for the next generation of fusion experiments. A feedthrough concept currently under investigation consists of a simple, cylindrical alumina ceramic brazed between tapered coaxia… more

Date: January 1, 1985

Creator: Owens, T. L.; Baity, F. W.; Hoffman, D. J. & Whealton, J. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three-dimensional calculations of fields and loading for loop and folded waveguide ICRF antennas

The ANT and ORION codes have been combined and used to study the loading of various antenna geometries with simple three-dimensional (3-D) effects. Both codes use a slab model with periodic Fourier analysis for modeling the toroidal and poloidal directions. The ANT code is used to prescribe current sets in a vacuum region where the field solutions are obtained analytically of each Fourier mode and matching conditions are used at poloidal/toroidal current sheet locations. Multiple current sheets… more

Date: January 1, 1991

Creator: Carter, M. D.; Baity, F. W.; Batchelor, D. B.; Hoffman, D. J.; Jaeger, E. F.; Swain, D. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ion Cyclotron Heating Experiments in EBT-S

Fast-wave heating and propagation experiments in the ion cyclotron range of frequencies (ICRF) have been carried out on EBT-S under steady-state conditions at power levels up to 20 kW and under pulsed conditions at power levels up to 100 kW. The waves were launched using a single Faraday-shielded loop antenna installed on the midplane of one of the 24 cavity sectors. Substantial ion heating was observed at frequencies above the second harmonic for hydrogen plasmas and at frequencies above the t… more

Date: January 1, 1982

Creator: Baity, F. W.; Davis, W. A.; Eldridge, O. C.; Glowienka, J. C.; Hillis, D. L.; Rasmussen, D. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Thermal and stress analysis of the Faraday shield for the ORNL/TFTR rf antenna

The rf antenna designed and built by Oak Ridge National Laboratory (ORNL) for the Tokamak Fusion Test Reactor (TFTR) is an ion cyclotron resonance heating antenna operating in the 40- to 80-MHz frequency range with a power output of 4 MW for a 2-s pulse. The antenna was delivered to Princeton in November 1987. A review of the antenna design began in early 1988 to ensure compatibility with D-T operation of TFTR. Owing to the serious consequences of a water leak during D-T operation and to other … more

Date: January 1, 1989

Creator: Hammonds, C. J.; Nelson, B. E.; Walls, J. C.; Hoffman, D. J. & Baity, F. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Rf vacuum feedthroughs

The development of rf vacuum feedthroughs is discussed. Two considerations of the development are given: impedance matching to the transmission line (measured by bandwidth) and the importance of a perpendicular orientation of the dielectric window relative to the electric fields. The report consists of 25 viewgraphs. (WRF)

Date: January 1, 1985

Creator: Raridon, R. J.; Whealton, J. H.; Bell, M. A.; Hoffman, D. J.; Baity, F. W. & Owens, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fundamental and second harmonic hydrogen fast-wave heating on DIII-D

Ion cyclotron resonance heating (ICRH) with fast waves has been investigated on D3-D in both the fundamental hydrogen minority (32 MHz, 2.14 T) and second harmonic hydrogen majority (60 MHz, 1.97 T) regimes. The main purpose of these experiments was to characterize the fast wave coupling and propagation in preparation for upcoming fast wave current drive (FWCD) experiments. For the fundamental minority regime, the electron and ion heating, global confinement, and radiated power fraction are com… more

Date: October 1, 1991

Creator: Petty, C. C.; Pinsker, R. I.; Mayberry, M. J.; Prater, R. (General Atomics, San Diego, CA (United States)); Porkolab, M.; Bonoli, P. T. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Technology of ICH systems for advanced fusion experiments

Work has been done at ORNL to improve existing ICRH technology for machines such as the Tore Supra. Improvements have been made in three components of the ICRH system: the antenna, Faraday shield, and rf vacuum feedthrough. Improvements in power handling capabilities and/or efficiency of a factor of 2-4 have been observed. The resulting overall improvement for the system is then 4-16. (WRF)

Date: January 1, 1985

Creator: Swain, D. W.; Baity, F. W.; Hoffman, D. J.; Owens, T. L. & Tsai, C. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fast wave current drive antenna performance on DIII-D

Fast wave current drive (FWCD) experiments at 60 MHz are being performed on the DIII-D tokamak for the first time in high electron temperature, high {beta} target plasmas. A four-element phased-array antenna is used to launch a directional wave spectrum with the peak n{sub {parallel}} value ({approx equal} 7) optimized for strong single-pass electron absorption due to electron Landau damping. For this experiment, high power FW injection (2 MW) must be accomplished without voltage breakdown in t… more

Date: October 1, 1991

Creator: Mayberry, M. J.; Pinsker, R. I.; Petty, C. C.; Chiu, S. C.; Jackson, G. L.; Lippmann, S. I. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ICRF antenna and feedthrough development at ORNL

The rf technology program at Oak Ridge National Laboratory is highlighted. Simply stated, the objective of the program is to develop the technology for ion cyclotron range of frequencies heating of the fusion machines leading up to a reactor. Results from an investigation of the importance of current strap shaping in compact antenna design are presented. Designs of the Doublet III-D and Advanced Toroidal Facility compact loop launchers are described, as are the vacuum feedthroughs for the West … more

Date: January 1, 1985

Creator: Baity, F. W.; Bryan, W. E.; Hoffman, D. J.; Owens, T. L.; Rettig, C. L. & Schechter, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Scaling in ELMO Bumpy Torus (EBT)

Basic operational principles of EBT are described. The scaling laws along with radial transport calculations are briefly discussed. (MOW)

Date: January 1, 1979

Creator: Baity, F. W.; Carpenter, K. H.; Cobble, J. A.; Colchin, R. J.; Eason, H. O.; Glowienka, J. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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30-60 MHz FWCD system on DIII-D: Power division, phase control and tuning for a four-element antenna array

The 2 MW Fast Wave Current Drive system on DIII-D is intended to provide a near-term demonstration of up to 0.3 MA of current driven by the fast wave. The system used to drive the four element phased antenna array which produces the required directional spectrum is presented. This system must be able to cope with strong coupling between antenna elements and the time-varying plasma load seen by the antennas. Computer modelling shows that this system should be able to maintain a directional spect… more

Date: November 1, 1991

Creator: Pinsker, R. I.; Mayberry, M. J.; Petty, C. C.; Cary, W. P.; Pusl, J.; Remsen, D. (General Atomics, San Diego, CA (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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3-D Analysis on Arbitrarily-Shaped Icrf Antennas and Faraday Shields

Cavity antennas with Faraday shields are proposed to couple ion cyclotron radio frequency power for heating fusion plasmas. This application requires small, high-power, low-frequency antennas. The results are presented of a theoretical study of the ICRF antennas being developed for this purpose at the Radio Frequency Test Facility (RFTF). The objectives of this work are to optimize experimental designs and to confirm test results. (MOW)

Date: January 1, 1986

Creator: Chen, G. L.; Whealton, J. H.; Baity, F. W.; Hoffman, D. J. & Owens, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ICRH coupling in DIII-D

A 9-MW ion cyclotron resonant frequency (ICRF) experiment has been proposed to heat the Doublet III-D (DIII-D) plasma. DIII-D is a 2.2-T, 3.5-MA tokamak at GA Technologies with a major radius of 1.67 m and minor radius of 67 cm (elongation approx.2). The device was recommissioned in early 1986. The initial experimental program includes ohmic plasma and neutral beam studies; high-power rf experiments will follow in later years. Compact loop antennas (which fit completely in a 35- by 50-cm port) … more

Date: January 1, 1986

Creator: Hoffman, D. J.; Baity, F. W.; Bryan, W. E.; Jaeger, E. F.; Owens, T. L.; Remsen, D. B. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ICRF Heating Technology Development Activities at Oak Ridge National Laboratory

The rf technology program at the Oak Ridge National Laboratory (ORNL) is developing the components needed for heating in the ion cyclotron range of frequencies (ICRF) on future fusion machines, such as the Compact Ignition Tokamak. Components produced in this program are already in use on experiments throughout the world, including Doublet III-D (DIII-D), TMX-U, Alcator-C, and TEXTOR. Designs have been developed for implementation on Tore Supra and ASDEX. Recent developments in vacuum feedthrou… more

Date: January 1, 1986

Creator: Baity, F. W.; Bryan, W. E.; Hoffman, D. J.; Schechter, D. E. & Owens, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental measurements of the ion cyclotron antennas' coupling and rf characteristics

The rf coupling capabilities and characteristics of various antennas have been measured. The tested antenna configurations include the simple loop antenna operated at resonant lengths as used on Alcator-C, the cavity antenna proposed for Doublet III-D and the resonant double loop, asymmetric resonant double loop, and U-slot antennas. Models of the voltage, magnetic fields outside the structure, and current have been correlated with the measurements made on these antennas. From these measurement… more

Date: January 1, 1985

Creator: Hoffman, D. J.; Baity, F. W.; Becraft, W. R.; Caughman, J. B. O. & Owens, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ICRF antenna designs for CIT and Alcator C-Mod

An ion cyclotron range of frequencies (ICRF) launcher for the Compact Ignition Tokamak (CIT) has been designed. This launcher incorporates four current straps in a 2 /times/ 2 configuration. The current straps consist of end-fed loops that are grounded in the middle. An antenna similar in geometry, size, and feed configuration to a single strap of the CIT launcher will be built for use on Alcator C-Mod. The design must provide maximum power levels of 4 MW/port for CIT and 2 MW/port for C-Mod, p… more

Date: January 1, 1989

Creator: Goulding, R. H.; Baity, F. W.; Goranson, P. L.; Hoffman, D. J.; Ryan, P. M.; Traylor, D. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design of an ion cyclotron resonance heating system for the Compact Ignition Tokamak

The Compact Ignition Tokamak (CIT) requires 10-20 MW of ion cyclotron resonance heating (ICRH) power to raise the plasma temperature to ignition. The initial ICRH system will provide 10 MW of power to the plasma, utilizing a total of six rf power units feeding six current straps in three ports. The systems may be expanded to 20 MW with additional rf power units, antennas, and ports. Plasma heating will be achieved through coupling to the fundamental ion cyclotron resonance of a /sup 3/He minori… more

Date: January 1, 1987

Creator: Yugo, J. J.; Goranson, P. L.; Swain, D. W.; Baity, F. W. & Vesey, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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EBT electron energy confinement experiments

Plasma parameters as measured in the EBT-S device are presented together with a description of ECH power modulation techniques applied to investigate the confinement properties of the EBT plasma.

Date: January 1, 1984

Creator: Wilgen, J. B.; Richards, R. K.; Hillis, D. L.; Swain, D. W.; White, T. L.; Peterson, B. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fast wave current drive system design for DIII-D

DIII-D has a major effort underway to develop the physics and technology of fast wave electron heating and current drive in conjunction with electron cyclotron heating. The present system consists of a four strap antenna driven by one 2 MW transmitter in the 32--60 MHz band. Experiments have been successful in demonstrating the physics of heating and current drive. In order to validate fast wave current drive for future machines a greater power capability is necessary to drive all of the plasma… more

Date: September 1, 1992

Creator: deGrassie, J. S.; Callis, R.; Lin-Liu, Y. R.; Moeller, C..; Petty, C. C.; Phelps, D. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Direct electron heating and current drive with fast waves in DIII-D

Experiments on the DIII-D tokamak have been performed to evaluate noninductive current drive with direct electron absorption of the fast Alfven wave (FW) in the ion cyclotron range of frequencies. These experiments have employed a 2 MW 60 NM transmitter connected to a four-element toroidally phased array of loop antennas located at the outside midplane of the DIII-D vacuum vessel. Efficient direct electron heating was obtained with (0, [pi], 0, [pi]) antenna phasing; H-mode confinement was obta… more

Date: September 1, 1992

Creator: Pinsker, R. I.; Petty, C. C.; Callis, R. W.; Cary, W. P.; Chiu, S. C.; Freeman, R. L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The design of high-power ICRF antennas for TFTR and Tore Supra

The Oak Ridge National Laboratory is designing, fabricating, and testing antennas for TFTR and Tore Supra. The antennas will deliver 4 MW per port to the hot plasma. The antennas' designs are nearly complete; they are backed by the results of extensive modeling, analyses, and tests of the electrical, thermal, and structural characteristics of the antennas that were carried out during the design process.

Date: January 1, 1987

Creator: Hoffman, D. J.; Baity, F. W.; Bryan, W. E.; Chen, G. L.; Luk, K. H.; Owens, T. L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Simulation of enhanced tokamak performance on DIII-D using fast wave current drive

The fast magnetosonic wave is now recognized to be a leading candidate for noninductive for the tokamak reactor due to the ability of the wave to penetrate to the hot dense core region. Fast wave current drive (FWCD) experiments on D3D have realized up to 120 kA of rf current drive, with up to 40% of the plasma current driven noninductively. The success of these experiments at 60 MHZ with a 2 MW transmitter source capability has led to a major upgrade of the FWCD system. Two additional transmit… more

Date: May 1, 1993

Creator: deGrassie, J. S.; Lin-Liu, Y. R. Petty, C. C.; Pinsker, R. I.; Chan, V. S.; Prater, R.; St. John, H. (General Atomics, San Diego, CA (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department