Currently, only one coupled neutron-photon multigroup library is supported by X-Division, MGXSNP. The library MGSXNP is comprised of 30-group neutron and 12-group photon data primarily based on ENDF/B-V for 95 nuclides. The MCNP-compatible multigroup data library was produced from the original Sn multigroup libraries MENDF5 and MENDF5G using the code CRSRD in April 1987. The original neutron data library, MENDF5, was produced using the "TD-Division Weight Function", also called "CLAW" by the processing code NJOY. This weight function is a combination of a Maxwellian thermal + 1/E + fission + fusion peak at 14.0 MeV. The data library contains no upscatter groups or self-shielding, and is most applicable for fast systems. All cross-sections are for room temperature, 300K. P0 through P4 scattering matrices from the original library were processed by CRSRD into angular distributions for MCNP using the Carter-Forest equi-probable bin treatment. When available, both total and prompt nubar data are provided. The edit reactions, as well as other information, are more fully described in the following PDF document: LA-UR-98-538.
MGXSNP can be downloaded either as a zip file or as a compressed tarball
If further information is required contact a member of the Data Team by e-mail at firstname.lastname@example.org