Fig. 4
From: Sympathetic cooling of molecular ions with ultracold atoms
The experimental and MD determinations of lnΛ versus g. Despite large variation in trap parameters the observed values fall along the same curve, indicating a universal form for lnΛ. The dashed black curve represents the analytical form used here and in [29] (modified to agree with low temperature data), while the other curves represent previous forms described elsewhere [27]. The top x-axis denotes the domain of this graph in terms of the plasma coupling parameter, Γ, which is the ratio of potential to kinetic energy