Chapter 7: Radio-Frequency Wave Physics in the FTU

Journal Article · Sat May 15 00:00:00 EDT 2004 · Fusion Science and Technology

OSTI ID:20849700

Granucci, G ^[1]; Airoldi, A ^[1]; Barbato, E ^[2]; Bruschi, A ^[1]; Cardinali, A ^[2]; Castaldo, C ^[2]; Cesario, R ^[2]; Cirant, S ^[1]; Esposito, B ^[2]; Farina, D ^[1]; Gandini, F ^[1]; Giruzzi, G ^[3]; Gormezano, C ^[2]; Leigheb, M ^[2]; Marinucci, M ^[2]; Mirizzi, F ^[2]; Nowak, S ^[1]; Panaccione, L ^[2]; Pericoli-Ridolfini, V ^[2]; Podda, S ^[2] ; Ramponi, G ^[1]; Ravera, G L ^[2]; Saveliev, A N ^[4]; Simonetto, A ^[1]; Sozzi, C ^[1]; Tuccillo, A A ^[2]; Zonca, F ^[2]

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1. Associazione EURATOM-ENEA-CNR sulla Fusione (Italy)
2. Associazione EURATOM-ENEA sulla Fusione (Italy)
3. Association EURATOM-CEA sur la Fusion (France)
4. A. F. Ioffe Physico-Technical Institute (Russian Federation)

This chapter reports the main physics results obtained with three radio-frequency-injection systems. The frequency of 8 GHz for the lower hybrid (LH) current drive (CD) (LHCD) system was chosen to explore CD at high density: full CD has been demonstrated for central densities up to 1.4 x 10{sup 20} m{sup -3} at 0.5 MA with an applied power up to 2.0 MW. The Frascati Tokamak Upgrade (FTU) database shows CD efficiencies from 0.1 to 0.3 x 10{sup 20} AW{sup -1} m{sup -2}. In combined experiments with electron cyclotron (EC) waves (140 GHz, up to 1.2 MW), a suprathermal absorption by the fast electron tail generated by LHCD has been observed in both downshifted and upshifted interaction regimes, with the resulting electron cyclotron current drive (ECCD) ranging from 20 to 100 kA, depending on experimental conditions. With pure EC resonance heating, the narrowness of the radial power deposition profile has been exploited, resulting in strong local electron heating. Results in high-density regimes are also presented. The third system (433 MHz, 0.5 MW) is the first to test ion Bernstein wave (IBW) coupling with a waveguide antenna. The experiment operates at high frequency, avoiding the occurrence of nonlinear phenomena at the edge. Improved confinement regimes resulting in a central peaking of the pressure profiles have been achieved with P{sub IBW} up to 0.4 MW. Modeling and experimental results are summarized.

• OSTI ID: 20849700
• Journal Information: Fusion Science and Technology, Vol. 45, Issue 3; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
BERNSTEIN MODE
COMPUTERIZED SIMULATION
ECR CURRENT DRIVE
EFFICIENCY
ELECTRONS
FT TOKAMAK
GHZ RANGE
IONS
LOWER HYBRID CURRENT DRIVE
LOWER HYBRID HEATING
MHZ RANGE
NONLINEAR PROBLEMS
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA SIMULATION
PLASMA WAVES
RADIOWAVE RADIATION
RESONANCE
WAVEGUIDES