Measuring relaxation times of fluid moments with a GPU-accelerated MD code

The molecular dynamics (MD) simulation is an intuitive and effective tool for analyzing collisional processes of a plasma. It can be used to compute the collision time by measuring the equilibration time of temperatures and momenta and the relaxation time of non-Maxwellian moments. Measuring the higher-order moments requires a large number of particles for small statistical fluctuations. The computation effort for N particles can be reduced from O(N²)to O(NlogN) by computing particle-multipole, instead of particle-particle, interactions. A GPU-accelerated MD code is developed to significantly reduce the wall-clock time of MD simulations. Numerical experiments with the code are performed to measure the equilibration and relaxation times of various fluid moments.