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in subjects: "High-Frequency Heating"

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MeV ion loss during sup 3 He minority heating in TFTR

The loss of MeV ions during {sup 3}He ICRH minority heating experiments has been measured using scintillator detectors near the wall of TFTR. The observed MeV ion losses to the bottom (90{degrees} poloidal) detector are generally consistent with the expected first-orbit loss of D-{sup 3}He alpha particle fusion products, with an inferred global reaction rate up to {approx}10{sup 16} reactions/sec. A qualitatively similar but unexpectedly large loss occurs 45{degrees} poloidally below the outer … more

Date: January 1, 1992

Creator: Zweben, S. J.; Hammett, G.; Boivin, R.; Phillips, C. & Wilson, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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An algorithm for the calculation of 3-D ICRF (Ion Cyclotron Range of Frequencies) fields in tokamak geometry

A computational scheme is developed which permits tractable calculation of three-dimensional full-wave solutions to the Maxwell-Vlasov equations under typical Ion Cyclotron Range of Frequencies (ICRF) experimental conditions. The method is unique in that power deposition to the plasma is determined via the anti-Hermitian part of a truncated warm-plasma dielectric operator, rather than as the result of an assumed phenomenological collision frequency. The resulting computer code allows arbitrary … more

Date: April 1, 1987

Creator: Smithe, D.N.; Colestock, P.L.; Kashuba, R.J. & Kammash, T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Ra: A high efficiency, D-/sup 3/He, tandem mirror fusion reactor: Appendix C

The Ra tandem mirror fusion reactor concept features inherent safety, high net plant efficiency, low cost of electricity, low radioactive waste generation, low activation, highly efficient direct conversion, thin radiation shields, and axisymmetric magnets. The safety and environmental features are achieved through the use of D/He-3 fuel, while the high efficiency derives from a new operating mode. ICRF stabilization allows an axisymmetric magnet set. 11 refs., 5 figs., 3 tabs.

Date: January 1, 1987

Creator: Santarius, J. F.; Attaya, H.; Corradini, M. L.; El-Guebaly, L. A.; Emmert, G. A.; Kulcinski, G. L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurements of optically thin electron cyclotron emission from relativistic electrons

Electron cyclotron emission (ECE) from hot, relativistic electrons has been measured simulataneously at several optically thin frequencies (f/f/sub ce/ = 4.6, 7.0, and 9.6) on the Tandem Mirror Experiment-Upgrade. A method to determine the temporal evolution of the hot electron density, n/sub h/, and temperature T/sub h/ is discussed. Calculations of T/sub h/ agree with the analysis of the high energy x-ray spectra. Heating rates vary between 3 keV/ms and 13 keV/ms and temperatures over 300 keV… more

Date: October 1, 1987

Creator: James, R. A.; Silver, E.; Boyd, D.; Ellis, R. F.; Jantz, S.; Lasnier, C. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Local entropy generation analysis

Second law analysis techniques have been widely used to evaluate the sources of irreversibility in components and systems of components but the evaluation of local sources of irreversibility in thermal processes has received little attention. While analytical procedures for evaluating local entropy generation have been developed, applications have been limited to fluid flows with analytical solutions for the velocity and temperature fields. The analysis of local entropy generation can be used t… more

Date: February 1, 1991

Creator: Drost, M. K. & White, M. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Proceedings of the 10th international workshop on ECR ion sources

This report contains papers on the following topics: Recent Developments and Future Projects on ECR Ion Sources; Operation of the New KVI ECR Ion Source at 10 GHz; Operational Experience and Status of the INS SF-ECR Ion Source; Results of the New ECR4'' 14.5 GHz ECRIS; Preliminary Performance of the AECR; Experimental Study of the Parallel and Perpendicular Particle Losses from an ECRIS Plasma; Plasma Instability in Electron Cyclotron Resonance Heated Ion Sources; The Hyperbolic Energ… more

Date: January 1, 1991

Creator: Meyer, F W & Kirkpatrick, M I

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mirror theory applied to toroidal systems

Central features of a mirror plasma are strong departures from Maxwellian distribution functions, ambipolar potentials and densities which vary along a field line, end losses, and the mirror field itself. To examine these features, mirror theorists have developed analytical and numerical techniques to solve the Fokker-Planck equation, evaluate the potentials consistent with the resulting distribution functions, and assess the microstability of these distributions. Various combinations of mirror… more

Date: August 25, 1987

Creator: Cohen, R.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ICRF heating in reactor grade plasmas

Impurity influxes in JET discharges due to ICRH have been reduced to insignificant levels. This has allowed high quality H-modes to be produced with ICRH alone and has enhanced the density limit which is now the same as the NBI limit. Improvement in the deuterium fuel fraction has led to the generation of 100kW of non thermal {sup 3}He-D fusion power. Alpha-particle simulations using MeV ions created by ICRH show classical energy loss and suggest that {alpha}-heating in a reactor will be highly… more

Date: January 1, 1990

Creator: Jacquinot, J.; Bhatnagar, V. P.; Bures, M.; Cottrell, G. A.; Eriksson, L. G.; Sack, C. H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effects of ion cyclotron harmonic damping on current drive in the lower hybrid frequency range

We investigate the ion cyclotron harmonic damping effects on slow and fast waves in the lower hybrid frequency range for tokamak reactor parameters. Inclusion of the higher order terms in the hot plasma dielectric tensor introduces ion cyclotron harmonic damping; these terms also contribute to the real part of the dispersion relation and affect the wave trajectories. However, wave absorption by 15 keV deuterium and tritium ions can be avoided by choosing the slow wave frequency above the lower … more

Date: November 1, 1983

Creator: Wong, K. L. & Ono, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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DIII-D results and plans

The completion of additional radiation shielding in the spring of 1989 has allowed the DIII-D tokamak to enter a new phase of experimental operation, in which the potential of injecting deuterium beam injection into deuterium plasmas has been exploited. The benefit of the isotope effect in increased energy confinement time, and increased power delivery by the neutral beam injectors, has been used to extend the machine performance. Plasma beta values ({beta}{sub T} {le} 10.7%) near expected theo… more

Date: September 1, 1990

Creator: Callis, R.; Anderson, P.; Colleraine, A.; Smith, J.; Petersen, P. & Taylor, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Auxiliary heating results from PDX and PLT

Auxiliary heating experiments are continuing on both PLT and PDX. PLT has increased the available ICRF power delivered to the plasma to 3 MW for the 42 MHz system and to 1.6 MW for the 25 MHz system. Deuteron and electron heating are observed in the minority /sup 3/He (T/sub d/ approx. 2.8 keV, T/sub e/ approx. 2.2 keV) and H (T/sub d/ approx. 2 keV, T/sub e/ approx. 2.5 keV) heating regimes. In addition, ion heating has been observed in the second harmonic regime (T/sub eff/ = 2/3 <E/sub h/> =… more

Date: September 1, 1982

Creator: Davis, S.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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ICRF Faraday shield plasma sheath physics: The Perkins paradigm

Using a 2-D nonlinear formulation which considers the plasma edge near a Faraday shield in a self consistent manner, progress is indicated in the modeling of the ion motion for a Perkins embodiment. Ambiguities in the formulation are also indicated, the resolution of which will provide significant insight into the impurities generation for ICRH antennas. 6 refs., 3 figs.

Date: January 1, 1989

Creator: Whealton, J.H.; Ryan, P.M. & Raridon, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Tests of a high-power folded waveguide coupler for ICRF heating

A full-scale folded waveguide coupler has been fabricated which will provide information on power handling, impedance matching, and multipactor effects. The coupler dimensions are 30 X 60 X 300 cm. The cross section of the coupler is small enough that a phased pair of couplers could be placed in a single Tore Supra or TFTR port. A single coupler could be placed in a CIT-size port. A movable back plate allows frequency adjustment over the range 78 to 140 MHz. Impedance matching at the waveguide … more

Date: January 1, 1987

Creator: Owens, T. L.; Chen, G. L.; Haste, G. R. & Ryan, P. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an … more

Date: May 11, 1988

Creator: Falabella, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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2 MW 110 GHz ECH heating system for DIII-D

A 2 MW 110 GHz ECH system using Varian 0.5 MW gyrotrons is under construction for use on the DIII-D tokamak by late 1991. Most of the components are being design and fabricated at General Atomics, including the gyrotron tanks, superconducting magnets, and transmission line. These components are intended for operation with 10 second pulses and, in the future, with 1 MW gyrotrons. 6 refs., 5 figs.

Date: September 1990

Creator: Moeller, C.; Prater, R.; Callis, R.; Remsen, D.; Doane, J.; Cary, W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cesium-plasma-conductivity enhancement in the advanced thermionic energy converter. Final report

Two methods of plasma conductivity enhancement in a cesium vapor thermionic energy converter have been studied. The first involved resonance photoabsorption of several cesium lines and the second utilized cesium plasma sustenance by application of microwave power. An extensive study of ionization processes in a cesium discharge in the presence of resonance ionization was made. Calculations were made of expected percentage excitation levels for several cesium resonance transitions for different … more

Date: unknown

Creator: Manikopoulos, C.N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High average power CW FELs (Free Electron Laser) for application to plasma heating: Designs and experiments

A short period wiggler (period {approximately} 1 cm), sheet beam FEL has been proposed as a low-cost source of high average power (1 MW) millimeter-wave radiation for plasma heating and space-based radar applications. Recent calculation and experiments have confirmed the feasibility of this concept in such critical areas as rf wall heating, intercepted beam ( body'') current, and high voltage (0.5 - 1 MV) sheet beam generation and propagation. Results of preliminary low-gain sheet beam FEL osci… more

Date: January 1, 1989

Creator: Booske, J. H.; Granatstein, V. L.; Radack, D. J.; Antonsen, T. M. Jr.; Bidwell, S.; Carmel, Y. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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ECH by FEL and gyrotron sources on the Microwave Tokamak Experiment (MTX) tokamak

The Microwave Tokamak Experiment (MTX) at LLNL is studying the physics of intense pulse ECH is a high-density tokamak plasma using a microwave FEL. Related technology development includes the FEL, a windowless quasi-optical transmission system, and other microwave components. Initial plasma experiments have been carried out at 140 GHz with single rf pulses generated using the ETA-II accelerator and the ELF wiggler. Peak power levels up to 0.2 GW and pulse durations up to 10 ns were achieved for… more

Date: August 9, 1990

Creator: Stallard, B. W.; Turner, W. C.; Allen, S. L.; Byers, J. A.; Felker, B.; Fenstermacher, M. E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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He self-pumping by tokamak pump limiter materials: Al, V, Ni, and Ni/Al alloys

An ECR plasma and Colutron ion gun were used to study He self-pumping by several possible pump-limiter materials: Ni, V, Al, and Ni/Al multi-layers. Ni and V exhibited similar pumping capacities (6 {times} 10{sup 15} He/cm{sup 2}, 200 eV) whereas Al showed a reduced capacity (6 {times} 10{sup 14} He/cm{sup 2}, 200 eV) due to increased sputtering. A He retention model based upon ion implantation ranges and sputtering rates agreed with the experimental data. The pumping efficiency increased signi… more

Date: January 1, 1991

Creator: Outten, C. A.; Barbour, J. C.; Doyle, B. L. & Walsh, D. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fast ion profiles during neutral beam and lower hybrid heating

Profiles of the d(d,p)t fusion reaction are measured in the PLT tokamak using an array of collimated 3 MeV proton detectors. During deuterium neutral beam injection, the emission profile indicates that the beam deposition is at least as narrow as predicted by a bounce-averaged Fokker-Planck code. The fast ion tail formed by lower hybrid waves (at densities above the critical density for current drive) also peaks strongly near the magnetic axis.

Date: July 1, 1985

Creator: Heidbrink, W. W.; Strachan, J. D.; Bell, R. E.; Cavallo, A.; Motley, R.; Schilling, G. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Dielectric changes in neutron-irradiated rf window materials

Ceramics used for windows in ECRH heating systems for magnetically-confined fusion reactors must retain adequate properties during and after intense neutron irradiation. Of particular concern is a decrease in transmissivity, a parameter inversely related to the product of dielectric constant K and loss tangent tandelta. Samples of polycrystalline Al/sub 2/O/sub 3/ and BeO were irradiated to 1 x 10/sup 26/ n/m/sup 2/ at 660K in the EBR-II fission reactor, and the above properties subsequently me… more

Date: January 1, 1987

Creator: Frost, H.M. & Clinard, F.W. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Comparison between the electron cyclotron current drive experiments on DIII-D and predictions for T-10

Electron cyclotron current drive has been demonstrated on the DIII-D tokamak in an experiment in which {approximately}1 MW of microwave power generated {approximately}50 kA of non-inductive current. The rf-generated portion was about 15% of the total current. On the T-10 tokamak, more than 3 MW of microwave power will be available for current generation, providing the possibility that all the plasma current could be maintained by this method. Fokker-Planck calculations using the code CQL3D and … more

Date: November 1, 1990

Creator: Lohr, J.; Harvey, R. W.; Luce, T. C.; Matsuda, Kyoko; Moeller, C. P.; Petty, C. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effect of deuteron temperature on iron forbidden line intensities in rf-heated tokamak plasmas

Two line ratios, the forbidden line at 845.5 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s/sup 2/2p /sup 2/P/sub 3/2/) to the allowed line at 135.7 A (2s/sup 2/2p /sup 2/P/sub 1/2/ - 2s2p/sup 2/ /sup 2/D/sub 3/2/) in Fe XXII and the forbidden line at 592.1 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 1/D/sub 2/) to the forbidden line at 1118.2 A (2s/sup 2/2p/sup 4/ /sup 3/P/sub 2/ - 2s/sup 2/2p/sup 4/ /sup 3/P/sub 1/) in Fe XIX, have been measured as the ion temperature-sensitive lin… more

Date: May 1, 1987

Creator: Sato, K.; Suckewer, S. & Wouters, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Observation of d(d,p)t reactions in the Princeton Large Torus

Protons from d(d,p)t fusion reactions have been observed in the Princeton Large Torus (PLT) using a surface-barrier detector. The time evolution of the escaping protons agrees with the d-d neutron evolution. The proton energy spectrum was measured during ohmic, lower-hybrid, and ICRF heating. The proton spectrum during lower-hybrid heating indicates non-thermal enhancement of the d-d fusion rate.

Date: September 1, 1982

Creator: Chrien, R. E. & Strachan, J. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department