Authors: Keyan Gootkin (University of Hawai'i), Colby Haggerty (University of Hawai'i)

Collisionless plasma turbulence is a ubiquitous process in the solar corona, the solar wind, and many different astrophysical environments; one which is expected to be important for non-thermal particle acceleration. Recent works have shown that energetic power law distributions are naturally generated in kinetic particle-in-cell (PIC) simulations of decaying turbulence, however, it remains unclear how the parameters of the turbulence are related to the characteristics of the non-thermal, ion distribution. In this work, we use a suite of 2.5D, hybrid-PIC simulations of decaying turbulence to study the effect of turbulent Mach number (M = <u>/√(T/m)) on the fraction of energy and power law slope of the energetic ions. We find that as the simulations transition from sub to supersonic, the fraction of energy in non-thermal particles increases dramatically, accounting for as much as 20% of the total thermal energy in the system, with power-law slopes reaching ~E^-2. We attribute these increases to the formation of shocks which can directly accelerate ions through shock drift acceleration, which will then undergo fermi-like accelerations to form the extended power law distribution. These results have implications for systems where supersonic turbulence is potentially occurring, such as the lower solar corona, the interaction regions between the solar wind and large planetary bodies, and even star-forming regions.