Publications by Denis St-Onge

Fluctuation dynamo in a weakly collisional plasma


DA St-Onge, MW Kunz, J Squire, AA Schekochihin

Fluctuation Dynamo in a Collisionless, Weakly Magnetized Plasma


DA St-Onge, MW Kunz

On non-local energy transfer via zonal flow in the Dimits shift


DA St-Onge

Zonostrophic instability driven by discrete particle noise

PHYSICS OF PLASMAS 24 (2017) ARTN 042107

DA St-Onge, JA Krommes

Kubo conductivity tensor for two- and three-dimensional magnetic nulls.

Physical review. E, Statistical, nonlinear, and soft matter physics 90 (2014) 033103-

DA St-Onge, RD Sydora

The complete Kubo conductivity tensor is computed in two- and three-dimensional linear magnetic null systems using collisionless single-particle simulations. Regions of chaotic charged-particle dynamics are constructed for each case. It is found that stochastic frequency mixing of particle bounce motion, as well as gyromotion, contribute significantly to the conductivity. The conductivity curves are well approximated by power laws over a certain frequency range and the ac conductivity is found to be an order of magnitude smaller than the dc value, leading to enhanced resistivity, particularly near the cyclotron frequency. The ac conductivities must be accounted for in computation of the total dissipation.

Glass transitions in one-, two-, three-, and four-dimensional binary Lennard-Jones systems.

Journal of physics. Condensed matter : an Institute of Physics journal 21 (2009) 035117-

R Brüning, DA St-Onge, S Patterson, W Kob

We investigate the calorimetric liquid-glass transition by performing simulations of a binary Lennard-Jones mixture in one through four dimensions. Starting at a high temperature, the systems are cooled to T = 0 and heated back to the ergodic liquid state at constant rates. Glass transitions are observed in two, three and four dimensions as a hysteresis between the cooling and heating curves. This hysteresis appears in the energy and pressure diagrams, and the scanning rate dependence of the area and height of the hysteresis can be described using power laws. The one-dimensional system does not experience a glass transition but its specific heat curve resembles the shape of the D≥2 results in the supercooled liquid regime above the glass transition. As D increases, the radial distribution functions reflect reduced geometric constraints. Nearest neighbor distances become smaller with increasing D due to interactions between nearest and next-nearest neighbors. Simulation data for the glasses are compared with crystal and melting data obtained with a Lennard-Jones system with only one type of particle and we find that with increasing D crystallization becomes increasingly more difficult.