Femtosecond time-resolved studies of the dynamics of noble-gas cluster explosions

We have examined the dynamics of noble-gas clusters, heated with high-inten sity laser radiation, using pump-probe experiments to temporally resolve th e expansion of the clusters. Absorption of the probe radiation is observed to reach a maximum for a particular time delay between pump and probe, depe ndent on the cluster size. For single-pulse experiments, we find that there is an optimal pulse width to maximize absorption for a given cluster size. Model calculations suggest that these effects are due to resonant heating of the spherical cluster plasma in full support of a hydrodynamic interpret ation of cluster interactions. [S1050-2917(99)51005-6]. PACS number(s): 36. 10.Gk.