Detection of the kinetic geodesic acoustic mode (KGAM) near the centre region of JIPPT-IIU tokamak plasmas

The broad and intense spectrum of the geodesic acoustic mode (GAM) oscillations near the magnetic axis of tokamak plasmas with Te/Ti 1 becomes narrow and weak during neutral beam heating. It then becomes wide and weak during third harmonics ICRF heating. The wide spectra of GAMs are generally consistent with recent kinetic GAM (KGAM) theories.