In this paper, results are presented concerning the excitation of discrete Alfvén wave (DAW) modes in the TORTUS tokamak. The experiments involved sweeping a single antenna in frequency to generate a number of DAW modes which were identified using magnetic probe arrays. With reliable mode identification, and a good number of modes observed, it was possible to estimate the central value of the safety factor for the discharges. It was found that the results could be explained by discharges with sharp profiles of density and central q values below unity. Results are also presented for deuterium and helium discharges, in which the spectrum up to the cyclotron frequency was investigated
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