| 1. |
- Mayoral, M. -L, et al.
(författare)
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Overview of Recent Results on Heating and Current Drive in the JET tokamak
- 2009
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Ingår i: RADIO FREQUENCY POWER IN PLASMAS. - : AIP. - 9780735407534 ; , s. 39-46
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Konferensbidrag (refereegranskat)abstract
- In this paper, significant results in the heating and current drive domains obtained at JET in the past few years following systems upgrade and dedicated experimental time, will be reviewed. Firstly, an overview of the new Ion Cyclotron Resonance Frequency (ICRF) heating capabilities will be presented i.e. results from the ITER-Like ICRF antenna (ILA), the use of External Conjugate-T and 3dB hybrid couplers to increase the ICRF power during ELMy H-mode, Furthermore, experiments to study the influence of the phasing of the ICRF antenna on power absorption and coupling will be described. Looking at Low Hybrid (I-H) issues for ITER, the effect of the location of gas injection on the LH coupling improvement at large launcher-separatrix distances will be discussed as the possibility to operate at ITER-relevant power densities. Experiments to characterise the LH power losses in the Scrape-Off-Layer (SOL) and to determine the LH wave absorption and current drive using power modulation will be shown. Finally, plasma rotation studies in the presence of ICRF heating with standard and enhanced JET toroidal field ripple will be presented.
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| 2. |
- Ongena, J., et al.
(författare)
-
Overview of recent results on Heating and Current Drive in JET
- 2007
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Ingår i: RADIO FREQUENCY POWER IN PLASMAS. - : AIP. ; , s. 249-256
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Konferensbidrag (refereegranskat)abstract
- Recent progress on heating and current drive on JET is reported. Topics discussed are: high power coupling of ICRF/LH at ITER relevant antenna/launcher-separatrix distances, succesfull demonstration of 3 dB couplers for ELM tolerance of the ICRF system, influence of ICRF on LH operation, rotation studies in plasma without external momentum with standard and enhanced JET toriodal field ripple, studies of different ICRF heating schemes and of NTM avoidance schemes using Ion Cyclotron Current Drive. A brief outlook on future plans for experiments at JET is given.
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| 3. |
- Panek, R., et al.
(författare)
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Anomalous ion diffusion and radial-electric-field generation in a turbulent edge plasma potential weakly correlated in time and space
- 2005
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Ingår i: Physica Scripta. - 0031-8949 .- 1402-4896. ; 72:4, s. 327-332
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Tidskriftsartikel (refereegranskat)abstract
- Using a simple model of tokamak-edge-plasma turbulence in the form of a spatially periodic and time-independent electrostatic potential, we have found recently a new type of anomalous impurity diffusion in this regime [1], [2]. In the present contribution, we estimate this diffusion in the test-particle approach for a real turbulent potential obtained in an experiment. A significant difference in the impurity dynannics between the Hamiltonian and drift approaches is observed. As an interesting consequence of these dynamics, the possibility of radial-electric-field generation in the turbulence regimes appears. This effect can be of importance in scenarios related to transport barriers.
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| 4. |
- Rantamäki, K., et al.
(författare)
-
LH wave coupling over ITER-like distances at JET
- 2007
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Ingår i: Radio Frequency Power in Plasmas. - : American Institute of Physics (AIP). - 0735404445 - 9780735404441 ; , s. 261-264
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Konferensbidrag (refereegranskat)abstract
- Good coupling of LH power at plasma-launcher distance of 15 cm has been obtained at JET. Near-gas injection is used to increase the density in front of the grill. The role of LH power in the density increase at constant gas level is demonstrated. For the first time at JET the temperature of the hot spots caused by parasitic absorption of LH power has been measured.
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