Fast ion effects on fishbones and n=1 kinks in JET simulated by a non-perturbative NOVA-KN code

New global nonperturbative hybrid code, NOVA-KN, and simulations of resonant type modes in JET plasmas driven by energetic H-minority ions are presented. The NOVA-KN code employs the ideal MHD description for the background plasma and treats non-perturbatively the fast particle kinetic response, which includes the fast ion finite orbit width (FOW) effect. In particular, the n = 1 fishbone mode, which is in precession drift resonance with fast ions, is studied. The NOVA-KN code is applied to model an n = 1 (f = 50 - 80kHz) MHD activity observed recently in JET low density plasma discharges with high fast ion (H-minority) energy content generated during the ICRH. This n = 1 MHD activity is interpreted as the instability of the n = 1 precession drift frequency fishbone modes. (author)