We investigate electron-ion recombination processes in clusters exposed to
intense extreme-ultraviolet (XUV) or near-infrared (NIR) pulses. Using the
technique of reionization of excited atoms from recombination (REAR), recently
introduced in Schütte et al (2014 Phys. Rev. Lett. 112 253401), a large
population of excited atoms, which are formed in the nanoplasma during cluster
expansion, is identified under both ionization conditions. For intense XUV
ionization of clusters, we find that the significance of recombination
increases for increasing cluster sizes. In addition, larger fragments are
strongly affected by recombination as well, as shown for the case of dimers.
We demonstrate that for mixed Ar–Xe clusters exposed to intense NIR pulses,
excited atoms and ions are preferentially formed in the Xe core. As a result
of electron-ion recombination, higher charge states of Xe are efficiently
suppressed, leading to an overall reduced expansion speed of the cluster core
in comparison to the shell
