The letter describes details of MHD modes observed on the LT-4 tokamak for 2 < qψ < 3 during rapid current ramping (İ ≥ 10 kA·ms−1) up from normal flat-top operation (I ∼ 60 kA). When İ ≥ 2.3 kA·ms−1, a pure m=5/n=2 mode is excited when 2.3 ≤ qψ ≤ 2.6. The frequencies for this mode are between 45 and 80 kHz and the amplitude is θ/Bθ ≤ 0.04%. When qψ increases through 2.3, an m=7/n=3 mode appears at a frequency of 80–105 kHz and an amplitude of up to 0.01%. The strong m=3/n=l mode normally observed for 2.7 ≤ qψ ≤ 3.0 during flat-top operation does not appear when the current is ramped downwards faster than at 0.6 kA·ms−1.
The non-resonant kink modes triggering strong sawtooth-like crashes in the EAST tokamak