Nonlinear gyrokinetics provides a suitable framework to describeshort-wavelength turbulence in magnetized laboratory and astrophysical plasmas.In the electrostatic limit, this system is known to exhibit a free energycascade towards small scales in (perpendicular) real and/or velocity space. Thedissipation of free energy is always due to collisions (no matter how weak thecollisionality), but may be spread out across a wide range of scales. Here, wefocus on freely-decaying 2D electrostatic turbulence on sub-ion-gyroradiusscales. An existing scaling theory for the turbulent cascade in the weaklycollisional limit is generalized to the moderately collisional regime. In thiscontext, non-universal power law scalings due to multiscale dissipation arepredicted, and this prediction is confirmed by means of direct numericalsimulations.
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