  A time resolved experiment to investigate the ultrafast dynamics following an
ion impact onto a solid surface requires an ultrashort ion pump pulse in
combination with a properly synchronized and time resolved probe. In order to
realize such an experiment, we have investigated a strategy to use femtosecond
laser photoionization of atoms entrained in a pulsed supersonic jet for the
production of sufficiently short ion pulses. While the generation of Ar$^{q+}$
ions was targeted in previous work, it has in the meantime been demonstrated
that argon is not suitable due to extensive cluster formation in the supersonic
expansion. Here, we therefore present numerical simulations investigating the
use of neon as a precursor gas and show the feasibility of pulses containing up
to ~1000 Ne$^{q+}$ ions at keV energies and picosecond duration. In the
process, we demonstrate that space charge broadening can be significantly
reduced by detuning the flight time focusing conditions of an ion bunching
system. Moreover, the results show that a controlled variation of the buncher
geometry and potentials permits the generation of picosecond pulses at variable
ion energy between 1 keV and 5 keV.
