  The quadrupole linear Paul trap is one of the key instruments in building
highly stable atomic clocks. However, a frequency reference based on a single
trapped ion is limited in stability due to the time needed for the
interrogation cycle which cannot be further shortened. A promising strategy is
the utilization of multiple trapped ions. The ions of the same kind then
repulse each other with the Coulomb force, which is countered by the
ponderomotive force of the time depended field in the trap. A few ions form a
chain along the axis of a linear Paul trap. Adding more ions (a few tens or
hundreds) gives rise to Coulomb crystals. We created an efficient simulation
code which calculates the motion of such collections of ions in quasistatic
radiofrequency fields of real linear quadrupole traps (including the
micromotion). We include a model for laser cooling of the ions. The simulation
tool can be used to study the formation and the dynamics of Coulomb crystals
under conditions corresponding to various experimental set-ups.
