3D Monte Carlo neutron and photon transport code MCMG

A collision mechanism based on material rather than nuclide is added in the 3D Monte Carlo neutron and photon transport parallel code MCMG. Geometry cells and surfaces can be dynamically extended. The period of the random number is extended to 261. Combination of multigroup and continuous cross-section transport is developed. The multigroup scattering is expanded to P5 and the upper scattering is considered. Various multigroup libraries can be easily equipped in the code. The same results with the experiments and the MCNP code are obtained for a series of modes. The computation speed of MCMG is 2-4 times faster than the MCNP code.