Fig. 5: Emergence of higher-frequency modes.
From: Observation of a reduced-turbulence regime with boron powder injection in a stellarator
a,b, Spectrogram (log10 (PSD)) of the line-integrated phase-contrast imaging signal for #166,256 (a) and #167,234 (b). The white dashed lines indicates the approximate time of the boron powder entering the plasma. c,d, Comparison of turbulence PSD for the B injection shot (red) and the reference shot (blue), at time before (dashed lines) and during (solid lines) powder injection, time averaged over a window of 0.4 s, in order to attenuate the variations due to the pulsed diagnostic neutral beam. The shaded areas represent the standard deviation in time.
