An improved photo-absorption cross section model for the physics models regime in MCNPX

Radiat Prot Dosimetry. 2005;116(1-4 Pt 2):264-9. doi: 10.1093/rpd/nci080.

Abstract

The photo-nuclear physics model capabilities utilising the CEM2k model implemented in the MCNPX code were improved > 100 MeV photon energy by basing the photon transport on experimental photo-absorption cross sections of nuclides rather than on free nucleon cross sections. Below 100 MeV, the photo-nuclear physics model now uses isotope-specific giant dipole resonance (GDR) photo-absorption cross sections that are provided to the code in a parameterised form on a data file. Adjustments of the photo-fission cross sections were implemented to match the BOFOD evaluated data through a CEM2k internal parameter. The physics models with these improvements are better equipped to supplement the tabulated data based photo-nuclear MCNPX capability for isotopes with missing tabulated data evaluations especially in the GDR region, and has improved its predictive power at energies above the GDR resonances.

Publication types

  • Evaluation Study

MeSH terms

  • Absorption
  • Computer Simulation
  • Linear Energy Transfer
  • Models, Statistical*
  • Monte Carlo Method
  • Nuclear Physics / methods*
  • Photons*
  • Radiation Protection / methods*
  • Radioisotopes / analysis*
  • Radiometry / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Software*

Substances

  • Radioisotopes