Steady-state fully non-inductive reverse shear scenarios with electron ITB and dominant bootstrap currentFunded under: FP5-EAECTP C
The relation between the safety factor profile, q, the electron transport and the bootstrap current is of crucial importance for predicting advanced scenarios in burning plasmas which will have dominant electron heating and small momentum input. In recent experiments in the Tokamak TCV, the full plasma current has been sustained with only off-axis co-current drive and bootstrap current. As soon as the EC power is turned on, the inductive current is set to zero. Therefore the current profile evolves from the original ohmic profile to the one driven by the off-axis beams without any externally applied loop voltage. Due to the resulting reverse shear profile an electron internal transport barrier (eITB) is formed and the bootstrap current increases up to 50% of the total plasma current. Adding heating or counter CD in the centre exhibits clear difference in the time evolution of the electron temperature profile. With less current driven in the centre, and therefore a more reversed q profile, the eITB is more pronounced and better global electron energy confinement time is obtained. Increasing plasma density and EC power, electron internal transport barrier discharges with up to 80% bootstrap current have been sustained in steady-state with no ohmic current.
Bibliographic Reference: A paper presented at: 19th IAEA Fusion Energy Conference. Organised by: International Atomic Energy Agency (IAEA). Held at: Lyon, France, October 14-19 2002.
Availability: Available online at: http://crppwww.epfl.ch/conferences/IAEA02/ Also published in EPFL Internal Report LRP 738/02, available free of charge from: École Polytechnique Fédérale de Lausanne, Ecublens, CH-1015 Lausanne. Fax: +41-21-6934747.
Record Number: 200315845 / Last updated on: 2003-01-31
Original language: en
Available languages: en