Origin of the ion-temperature discrepancy

Determine whether the discrepancy between the simulated and experimentally observed ion temperatures in ultracold calcium plasma expansion under a constant, homogeneous magnetic field is caused by the regularization parameter r₀, the number of simulated particles, or both.

Background

The simulations reproduce the experimentally measured plasma expansion dynamics but disagree with experimental data concerning the ion temperature: the simulations predict that a higher initial electron temperature produces a higher ion temperature, whereas the cited experiment reports the opposite trend. The authors identify the regularization parameter r₀ and the particle number as possible sources of this discrepancy, but do not determine which, if either, is responsible. They further suggest comparing laser-induced-fluorescence spectra from experiments with spectra calculated from molecular-dynamics simulations.