On the dominant mechanisms of ion energization in collisionless plasma turbulence

Turbulence is ubiquitous in space and astrophysical plasmas, and it plays a crucial role in energy dissipation and plasma energization. However, the exact mechanism for particle energization in turbulent plasma is not fully understood. This study utilizes a fluid framework, which does not rely on the guiding-center approximation, to quantitatively analyze ion energization in turbulence by using observational data from the Magnetospheric Multiscale Mission (MMS) in the Earth’s magnetosheath, revealing the dominant role of the diamagnetic drift in ion energization. This research further demonstrates that ion energization occurs concentrated around the ion inertia length. However, in contrast to electrons, the relationship between ion energization/heating and coherent structures remains unclear and requires further research. This study provides new perspectives for understanding turbulent energy dissipation and particle heating.