  Monte Carlo computer simulations of a quasi two dimensional (2D) dipolar
fluid at low and intermediate densities indicate that the structure of the
fluid is well described by an ideal mixture of self-assembling clusters. A
detailed analysis of the topology of the clusters, of their internal energy and
of their size (or mass) distributions further suggests that the system
undergoes a phase transition from a dilute phase characterized by a number of
disconnected clusters to a condensed phase characterized by a network or
spanning (macroscopic) cluster that includes most of the particles in the
system.
