Multifractal scaling and intermittency in hybrid Vlasov-Maxwell simulations of plasma turbulence

By employing Hybrid Vlasov-Maxwell simulations in 2D-3V phase space configuration (2D in physical space and 3D in velocity space) of plasma turbulence, the statistical properties of the energy cascade at kinetic scales have been investigated. High-order moments of the magnetic field fluctuations have been inspected in order to quantify the intermittency phenomenon. At scales l larger than the ion skin depth d(i), fluctuations exhibit anomalous scaling, suggesting the presence of a multifractal intermittent turbulent cascade. For l < d(i), fluctuations show monoscaling, indicating Gaussian statistics. This scenario is consistent with the statistics of the dissipation fields J . E and J(2), suggesting that the processes of dissipation, intended as a conversion of energy from electromagnetic fluctuations to electron Ohmic heating and non-thermal proton effects, occur non-homogeneously in space. (C) 2016 AIP Publishing LLC.