Fig. 2: Variation in spectra of the invariants of gyro-kinetics.
From: Evidence of entropy cascade in collisionless magnetized plasma turbulence
The free energy Wg1(k⊥, p) and the electrostatic energy Eg(k⊥) for varied driving perpendicular wavenumbers kdriveρthi between ~0 and 10, (the 1st column) kdriveρthi ~ 1, (the 2nd column) kdriveρthi ~ 3−4, (the 3rd column) kdriveρthi ~ 0−4, and (the 4th column) kdriveρthi ~ 10, respectively. The plots in the 1st row (a–d) are the power spectra of potential fluctuation \({|{\tilde{\phi }}_{f}(f,{k}_{x})|}^{2}\) measured by FSLP. The plots shown in the 2nd row (e−h) are Wg1(k⊥, p) in the k⊥- p-space, namely, position–velocity-space. The 3rd row (i−l) are (cross) 1D spectra Wg11D of the free energy as functions of kxρthi and (open square) p-spectra of Wg1(p), respectively. Eg(k⊥) spectra are shown in the 4th row (m−p). Respective kdriveρthi ranges are shown by purple color bars. The blue and red bars represent power laws predicted by the gyrokinetic theory20 for (blue) k⊥ < kdrive and (red) k⊥ > kdrive, respectively.
