MOCCA: Dynamics and evolution of binary stars of multiple stellar
  populations in tidally filling and underfilling globular star clusters
  We present a new upgraded version of the MOCCA code for the study of
dynamical evolution of globular clusters and its first application to the study
of evolution of multiple stellar populations. We explore a range of initial
conditions spanning different structural parameters for the first (FG) and
second population (SG) and we analyze their effect on the binary dynamics and
survival. The set of simulations shown here represents the first phase of the
new MOCCA-SURVEY-2 project which will be further extended. Here, we focus our
attention on the number ratio of FG and SG binaries, its variation with the
distance from the cluster center, and the way their abundances are affected by
various cluster initial properties. We find that SG stars more abundant in
clusters that were initially tidally filling. Conversely, FG stars stay more
abundant in clusters that were initially tidally underfilling. We also find
that the ratio between binary fractions is not affected by the way we calculate
these fractions (e.g. with the use of all binaries, only main-sequence binaries
or observational binaries, i.e. main-sequence stars > 0.4 MSun, mass ratios >
0.5). We find also that the evolution of mixing between populations presents
the same features even if we take into account all single stars too. This
implies that the main-sequence stars themselves are a very good proxy for
probing entire populations of FG and SG in star clusters.
  We also discuss how our findings relate to the observations of Milky Way GCs.
We show that with MOCCA models we are able to reproduce the observed range of
SG fractions for any Milky Way GC for which we know this fraction. We show how
the SG fractions depend on the initial conditions. We provide also an
explanation what could be the initial conditions of star clusters, which at the
Hubble time, have more numerous FG, and which more numerous SG stars.
