First Evidence for the Existence of Odd Toroidal Alfvén Eigenmodes (TAEs) from the Simultaneous Observation of Even and Odd TAEs on the Joint European Torus
Authors: G.J. Kramer, S.E. Sharapov, R. Nazikian, N.N. Gorelenkov, R. Budny, and JET-EFDA contributors
Date of PPPL Report: January 2003
Published as: Observation of Odd Toroidal Alfvén Eigenmodes in Phys. Rev. Lett. 92 (9 January 2004) Article 015001/1-4.
Experimental evidence is presented for the existence of the theoretically predicted odd Torodicity-induced Alfvén Eigenmode (TAEs) from the simultaneous appearance of odd and even TAEs in a normal shear discharge. The modes are observed in low central magnetic shear plasmas created by injecting lower hybrid current drive. A fast ion population was created by applying ion cyclotron heating at the high field side to excite the TAEs in the weak magnetic shear region. The odd TAEs were identified from their frequency, mode number, and timing relative to the even TAEs.