An error in the journal production process led to figures 6 and 7 being incorrectly printed. The correct versions are given below. Figure 6. Power deposition profiles from high-frequency power modulation experiments (points) (Hartfuss H J 1994 Plasma Phys. Control. Fusion 36 B17) and a maximum entropy analysis of the ordinary heat pulses (dotted) compared with the profile required in order to describe the power-stepping experiments with a continuous model for × (dashed). Figure 7. Illustration of a heat pulse as produced by a non-locally reacting ×.