Measurements of the tokamak safety factor profile by means of driven resonant Alfvèn waves
The report presents the first measurements of the safety factor profile in a tokamak using the dispersion properties of Alfvèn-waves. The waves were launched using the TCA Alfvèn wave heating antennae, which allowed the resonant excitation of Alfvèn waves with defined mode numbers. The associated density oscillation profiles provided the shear Alfvèn-wave resonance layer positions which, for non-zero poloidal mode numbers, depend on the local value of the safety factor, q. Results for sawtoothing discharges with different plasma currents show a time-averaged q-profile with a flat central region where q is within a few percent of unity.
Bibliographic Reference: Report: LRP 372/89 EN (1989)
Availability: Available from Confédération Suisse, Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, 21 avenue des Bains, 1007 Lausanne (CH)
Record Number: 198910681 / Last updated on: 1994-12-01
Original language: en
Available languages: en