Author: J. HoseaPublisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
ICRF Heating During DT Experiments on TFTR
Author: J. HoseaICRF Heating During DT Experiments on TFTR
Author: J. HoseaICRF Heating and Current Drive Experiments on TFTR.
Author: J. H. RogersPublisher:
ISBN:
Category : Tokamak Fusion Test Reactor (Project).
Languages : en
Pages : 7
Book Description
ICRF Heating of Deuterium-tritium Plasmas in TFTR.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 13
Book Description
The first experiments to heat D-T plasmas in the ion cyclotron range of frequencies (ICRF) have been performed on the Tokamak Fusion Test Reactor (TFTR). These experiments have two major objectives: to study the RF physics of ICRF-heated D-T plasmas and to enhance the performance of D-T discharges. Experiments have been conducted at 43 MHz with out-of-phase current strap excitation to explore n{sub T}/n{sub e} concentrations up to approximately 40%. In these experiments n{sub T}/n{sub e} was limited by D recycling from the carbon walls. The location of the T resonance was varied by changing the toroidal magnetic field, and the RF power was modulated (f{sub mod} = 5--10 Hz) to elucidate competing heating mechanisms. Up to 5.8 MW of ICRF heating has been coupled into D-T plasmas. The addition of 5.5 MW of ICRF heating on a D-T supershot resulted in an increase in central ion temperature from 26 to 36 keV and an increase in central electron temperature from 8 to 10.5 keV. Up to 80% of the absorbed ICRF power was coupled directly to ions, in good agreement with computer code predictions. These results extrapolate to efficient T heating in future devices such as ITER.
Energy Research Abstracts
Author: ICRF Direct Electron Heating Experiments in TFTR.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
Direct electron damping of the fast wave is a prerequisite to a viable current drive scenario for future steady-state tokamaks. It is also an attractive heating altemative to the standard ion resonance heating methods for DT experiments on TFTR because it does not require the addition of non-reactive ion species and avoids minority ion tails during studies of alpha-particle effects. The absence of minority ions in direct electron heating (DEH) also allows the use of RF power modulation to determine power deposition profiles and to carry out modulation transport studies to characterize electron transport in supershot plasmas, as described in this paper.
ICRF Heating and Transport of Deuterium-tritium Plasmas in TFTR.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
This paper describes results of the first experiments utilizing high-power ion cyclotron range of frequency (ICRF) to heat deuterium-tritium (D-T) plasmas in reactor-relevant regimes on the Tokamak Fusion Test Reactor (TFTR). Results from these experiments have demonstrated efficient core, second harmonic, tritium beating of D-T supershot plasmas with tritium concentrations ranging from 6%-40%. Significant direct ion heating on the order of 60% of the input radio frequency (rf) power has been observed. The measured deposition profiles are in good agreement with two-dimensional modeling code predictions. Energy confinement in an rf-heated supershot is at least similar to that without rf, and possibly better in the electron channel. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves (IBW) has been demonstrated in ohmic, deuterium-deuterium and DT-neutral beam injection plasmas with high concentrations of minority 3He (n{sub 3He}/n{sub e} = 15% - 30%). By changing the 3He concentration or the toroidal field strength, the location of the mode-conversion radius was varied. The power deposition profile measured with rf power modulation indicated that up to 70% of the power can be deposited on electrons at an off-axis position. Preliminary results with up to 4 MW coupled into the plasma by 90-degree phased antennas showed directional propagation of the mode-converted IBW. Analysis of heat wave propagation showed no strong inward thermal pinch in off-axis heating of an ohmically-heated target plasma in TFTR.
ICRF Heating of TFTR Deuterium Supershot Plasmas in the 3He Minority Regime
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 36
Book Description
The increased core electron temperature produced by ICRF heating of TFTR, D-T neutral-beam-heated supershot plasmas is expected to extend the alpha particle slowing down time and hence enhance the central alpha particle pressure. In preparation for the TFTR D-T operational phase, which is due to start in late 1993, a series of experiments were conducted on TFTR to explore the effect of ICRF heating on the performance and stability of low recycling, deuterium supershot plasmas in the 3He minority heating regime. The coupling of up to 7.4 MW of 47 MHz ICRF power to full size, 3He minority, deuterium supershots heated with up to 30 MW of deuterium neutral beam injection has resulted in a significant increase in core electron temperature. Simulations of equivalent D-T supershots predict that such ICRF heating should result in approximately a 60% increase in the alpha particle slowing down time and an enhancement of about 30% in the central alpha pressure. Future experiments to be conducted at ICRF powers up to 12.5 MW during the upcoming TFTR D-T campaign may result in even greater enhancements in core alpha parameters. This paper presents results from experiments performed at an axial toroidal magnetic field of (approximately)4.8T, where the minority resonance was within 0.1--0.15 m of the plasma core. Combined ICRF and neutral beam heating powers in these experiments reached TFTR record levels of over 37 MW, which allowed an exploration of the power loading limits on the carbon limiter tiles. The plasma current was operated at 1.85 and 2.2 MA and sawtooth suppression was observed at the higher plasma current.
Diagnostics for Experimental Thermonuclear Fusion Reactors 2
Author: Peter E. StottPublisher: Springer Science & Business Media
ISBN: 1461553539
Category : Science
Languages : en
Pages : 615
Book Description
This book of proceedings collects the papers presented at the workshop on "Diagnostics for Experimental Fusion Reactors" held at Villa Monastero, Varenna (Italy) September 4-12, 1997. This workshop was the seventh organized by the International School of Plasma Physics "Piero Caldirola" on the topic of plasma diagnostics and the second devoted to the diagnostic studies for the International Thermonuclear Experimental Reactor (ITER). The proceedings of the first workshop on ITER diagnostics were published by Plenum Press in 1996 with the title "Diagnostics for Experimental Thermonuclear Fusion Reactors". While many of the ideas and studies reported in the first workshop remain valid, there has been sub stantial progress in the design and specification of many diagnostics for ITER. This moti vated a second workshop on this topic and the publication of a new book of proceedings. ITER is a joint venture between Europe, Japan, Russia and USA in the field of con trolled thermonuclear fusion research. The present aim of ITER is to design an experimental fusion reactor that can demonstrate ignition and sustained burn in a magnetically confined plasma. To achieve this goal, a wide range of plasma parameters will have to be measured reliably. It is also anticipated that diagnostics will be used much more extensively as input to control systems on ITER than on present fusion devices and this will require increased relia bility and long-term stability.
Author: M. G. Bell