Comparison of the results from full-PIC and MHD-PIC simulations using identical parameters as in run PIC-3 given in Table 2. The top panel presents the average magnetic energy evolution in time for full-PIC (blue solid line) and MHD-PIC (red solid line) techniques. The inset shows the full time-evolution from MHD-PIC simulation, as it runs over a much longer timescale than any full-PIC run. The bottom panel shows the comparison of wave spectra at the time that corresponds to the final time of the full-PIC simulation. Blue and red solid lines show the spectra from full-PIC for right- and left-handed modes, respectively. Green and orange solid lines show the same for MHD-PIC simulation. Note: the spectra from MHD-PIC simulation were upshifted by a factor of ≈ 2 in order to get a better visual comparison.