Evolution of Temperature in the Ultracold Strongly-Correlated Plasmas

TL;DR

This paper explains the temperature evolution in ultracold strongly-correlated plasmas, showing it becomes independent of initial conditions and follows a t^{-1} asymptotic, due to virialization rather than inelastic heating, supported by simulations.

Contribution

It introduces a virialization-based model to explain temperature dynamics in ultracold plasmas, contrasting with previous inelastic process explanations.

Findings

Temperature becomes independent of initial parameters at large times.

Temperature asymptotically follows a t^{-1} decay.

Simulations confirm the virialization model's validity.

Abstract

We present a theoretical interpretation of the recently revealed features of temperature evolution in the ultracold plasma clouds released from a magneto-optical trap, namely: (a) its independence at the sufficiently large times on the initial plasma parameters and (b) the asymptotics close to t^{-1} instead of t^{-2}, expected for a rarefied ideal gas. It is shown that both these properties can be well explained by the model of virialization of the charged particle velocities in the regime of strong electron-ion correlations, while heating due to inelastic processes (e.g. three-body recombination) should be of secondary importance. These conclusions are confirmed also by the results of ab initio computer simulations.