VIM continuous energy Monte Carlo transport code

VIM is a continuous energy neutron and photon transport code. VIM solves the steady-state neutron or photon transport problem in any detailed three-dimensional geometry using either continuous energy-dependent ENDF nuclear data or multigroup cross sections. Neutron transport is carried out in a criticality mode, or in a fixed source mode (optionally incorporating subcritical multiplication). Photon transport is simulated in the fixed source mode. The geometry options are infinite medium, combinatorial geometry, and hexagonal or rectangular lattices of combinatorial geometry unit cells, and rectangular lattices of cells of assembled plates. Boundary conditions include vacuum, specular and white reflection, and periodic boundaries for reactor cell calculations. VIM was developed primarily as a reactor criticality code. Its tally and edit features are very easy to use, and automatically provide fission, fission production, absorption, capture, elastic scattering, inelastic scattering, and (n,2n) reaction rates for each edit region, edit energy group, and isotope, as well as the corresponding macroscopic information, including group scalar fluxes. Microscopic and macroscopic cross sections, including microscopic PN group-to-group cross sections are also easily produced