Cluster-assisted multiple ionization of xenon and krypton by a nanosecond laser

Abstract

Multicharged xenon and krypton ions with charge states up to ${\mathrm{Xe}}^{11+}$ and ${\mathrm{Kr}}^{11+}$ have been observed in laser ionization of a pulsed xenon or krypton beam by a $25\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ Nd-YAG laser with laser intensity of ${10}^{10}--{10}^{11}\phantom{\rule{0.3em}{0ex}}\mathrm{W}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ at $532\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. There is strong evidence to support that those multicharged ions come from cluster-assisted electron recolliding ionizations inside the cluster after multiphoton ionization of atoms in the cluster, the electron can gain its kinetic energy by inverse bremsstrahlung absorption from a laser field quickly.