  The concentration profiles of monomers and counterions in star-branched
polyelectrolyte micelles are calculated through Monte-Carlo simulations, using
the simplest freely-jointed chain model. We have investigated the onset of
different regimes corresponding to the spherical and Manning condensation of
counterions as a function of the strength of the Coulomb coupling. The
Monte-Carlo results are in fair agreement with the predictions of
Self-Consistent-Field analytical models. We have simulated a real system of
diblock copolymer micelles of (sodium-polystyrene-sulfonate)(NaPSS)--
(polyethylene-- propylene)(PEP) with f=54 hydrophilic branches of N=251
monomers at room temperature in salt-free solution and compared the calculated
form factor with our neutron-scattering data.
