JET-C(98)64
Observation of Neo-classical Tearing Modes in JET
Neo-classical tearing modes have been identified in JET ELMy H-mode discharges at medium to high beta. The n=2 modes as observed in both ECE and SXR data, have a clear island structure and a global character. The critical normalised beta at the onset of the modes is found to scale with the normalised Larmor radius. The scaling with collisionality is much weaker and has a negative power.