We consider a mechanism for electron heating in atomic clusters at the reflections of free electrons from the cluster surface. Electrons acquire energy from the external laser field during these reflections. A simple analytical expression has been obtained for acquired electron kinetic energy during the laser pulse. We find conditions when this mechanism dominates compared to the electron heating due to the well-known induced inverse bremsstrahlung at the electron-ion collisions inside clusters.

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Various mechanisms of recombination of electrons with multiply charged atomic ions in atomic clusters irradiated by superintense femtosecond laser pulses are discussed. Some of the recombination mechanisms are shown to take a time considerably longer than the laser pulse duration and, hence, they can develop only in a homogeneous, fairly rarefied cluster plasma after pulse termination. All autoionization states of multiply charged ions in a dense cluster plasma have been found to be destroyed by the Holtsmark electric field. Therefore dielectric recombination does not take place in irradiated clusters during the laser pulse. Only collision recombination electron -ion -electron occurs effectively in dense cluster plasma due to high charge multiplicity of produced atomic ions inside the cluster.

Simple analytic expressions have been obtained for the relativistic electron drift in an ultra-short laser pulse along the pulse propagation in vacuum, or in underdense plasma. If an electron initially is at rest, the drift is exponentially small even in a super-intense laser pulse. The drift velocity becomes a relativistic quantity only when an electron is produced suddenly during the laser pulse at the tunnelling, or barrier-suppression ionization. Analytical estimates are obtained also for the drift velocity in this case.