Jimenez-Gomez, RKonies, AxelAscasibar, ECastejon, F.Estrada, T.Eliseev, L. G.Melnikov, A. V.Jimenez, J.A.Pretty, DavidJimenez-Rey, D.Pedrosa, M.A.de Bustos, A.Yamamoto, S.2015-12-102015-12-100029-5515http://hdl.handle.net/1885/68512High frequency modes (150-300 kHz) are found in several magnetic configurations of TJ-II plasmas heated by neutral beam injection (NBI). The clear dependence of mode frequency on plasma density and mass species suggests them to be Alfvén eigenmodes. TheKeywords: Eigen modes; Fast ions; Frequency chirping; Heavy ion beam probes; High-frequency mode; Ion loss; Low-order rational surfaces; Magnetic coil; Magnetic configuration; Mode frequencies; Neutral beam injection; Plasma profiles; Radial profiles; Rotational tr201110.1088/0029-5515/51/3/0330012016-02-24