Particle simulation of open-field plasmas in magnetic confinement systems is required to validate various physics models introduced to fluid simulations. An advanced particle simulation code PARASOL was developed, in which a binary collision model is incorporated to an electrostatic particle-in-cell (PIC) method. The simulation model is described in detail. Boundary conditions at the sheath entrance obtained by PARASOL simulations are shown. Effects of E×B drift, diffusive loss, and radiative cooling are studied. Heat transport along magnetic field is also investigated.