Parallel TREE code for two-component ultracold plasma analysis

TL;DR

This paper presents a parallelized TREE code tailored for simulating large-scale two-component ultracold plasmas, enabling efficient long-term dynamics analysis of systems with millions of particles.

Contribution

The authors developed a scalable parallel TREE algorithm specifically designed for two-component ultracold plasma simulations with non-uniform charge distributions.

Findings

Achieved high parallel efficiency for large ultracold plasma systems.

Successfully simulated systems with half a million particles over millions of time steps.

Enabled investigation of long-term relaxation dynamics in ultracold plasmas.

Abstract

The TREE method has been widely used for long-range interaction {\it N}-body problems. We have developed a parallel TREE code for two-component classical plasmas with open boundary conditions and highly non-uniform charge distributions. The program efficiently handles millions of particles evolved over long relaxation times requiring millions of time steps. Appropriate domain decomposition and dynamic data management were employed, and large-scale parallel processing was achieved using an intermediate level of granularity of domain decomposition and ghost TREE communication. Even though the computational load is not fully distributed in fine grains, high parallel efficiency was achieved for ultracold plasma systems of charged particles. As an application, we performed simulations of an ultracold neutral plasma with a half million particles and a half million time steps. For the long temporal trajectories of relaxation between heavy ions and light electrons, large configurations of ultracold plasmas can now be investigated, which was not possible in past studies.