MCNPX advances for accelerator applications

MCNPX is the Monte Carlo N-Particle extended version of MCNP. MCNPX transports 34 different particle types up to the terravolt energy range and was originally developed specifically for accelerator applications. In the past 2 years, many significant advances have been made that are of particular interest to the accelerator community. The upgrade to MCNP4C includes delayed neutrons, unresolved resonance range probability tables for neutron cross sections, extensions to ENDF/B-VI formats, and an electron physics upgrade. Also available from MCNP4C are superimposed-mesh weight windows, macrobody geometries, and interactive geometty plotting. MCNPX is now fully PC compatible with both Windows and Linux and supports distributed memory multiprocessing for the entire range of all particles. There are also many entirely new capabilities. MCNPX has been modernized to F90. Color geometry plots allow 64 colors and coloring by most parameters. Photonuclear data and proton cross sections now may be plotted. Many user conveniences have been added, such as default dose functions, logarithmic interpolation of tally bins, and easier source specification. Physics enhancements include positron sources, a spontaneous fission model, fission multiplicity, ³He coincidence modeling, and light-ion recoil. The MCNPX CEM physics model has been upgraded from CEM95 to CEM2k and a photonuclear physics model has been added. MCNPX can now mix and match physics models and data tables. It is now possible to specify some nuclides with models and other nuclides with data tables. It is also possible to use data tables up to their maximum energy value and then use models above that energy, even when the maximum table energy differs from nuclide to nuclide.