FWEH Induced High Bootstrap Current on Tore Supra
- Association Euratom-CEA, Centre d`Etudes de Cadarache, F-13108 - Saint-Paul-lez-Durance (France). Dept. sur la Fusion Controlee
- Oak Ridge National Lab., TN (United States)
Bootstrap current is regarded as a good candidate to sustain a large fraction of the plasma current, in the so-called `advanced` regimes of a tokamak reactor. It is thus important to study the stability of such discharges and to control them. By means of fast wave electron heating (FWEH, up to 9.5 MW), stationary high bootstrap discharges (during 5 seconds, Angstrom 40 %) were routinely obtained on Tore Supra. The bootstrap profile is computed with a matrix formulation (1,2) and is directly compared to the calculation of the non-inductive current. The simulation of the loop voltage either with the code CRONOS (1D current diffusion code) using the profile of bootstrap current, or with the knowledge of the resistivity, allows also a self consistent determination of the bootstrap current. First results show that the energy enhancement factor H increases linearly with the fraction of bootstrap current. The bootstrap induced by the FWEH is mainly due to the central pressure electron gradient (the central power deposition strongly peaks the electronic temperature). A 0D study shows that the bootstrap current (I{sub bs}) varies linearly with the poloidal beta (I{sub bs}/I{sub p} = C{sub bs} x {beta}{sub p}). The effect of various plasma parameters (toroidal field B{sub t}, line-integrated density nI, ion and electron temperature, plasma current I{sub p}) on the bootstrap profile, fraction, C{sub bs} and on the confinement are analysed.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 621553
- Report Number(s):
- CONF-9704102-18; ON: DE97009357; BR: AT5010702; TRN: AD-A332 07
- Resource Relation:
- Conference: 12. topical conference on radio frequency power in plasmas, Savannah, GA (United States), 1-3 Apr 1997; Other Information: DN: Presented at 12th Topical Conference on Radio Frequency Power in Plasma.[540 709900]; PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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