Progress on Light-Element Standard Cross Sections at Los Alamos [Slides]
Presenters identified the following statuses of the light-element standards: Extension of N-N scattering analysis to 200 MeV will likely come in time for ENDF/B VIII.1 and new data are to be added even in the energy range up to 100 MeV; for n- 3 He, a more recent 4 He R-matrix analysis from which updated n+ 3 He cross sections could be obtained for ENDF/B VIII.1; for n- 6 Li, more work is required to get a reasonable fit to all data up to E n = 8 MeV. Of particular concern are the t+ 4 He scattering data at E t > 14 MeV. For n- 10 B, new work on the 11 B system has not yet been started and there is much new data to add for n+ 10 B reactions, and maybe also for α + 7 Li reactions. The proliferation of excited-state channels will limit the upper neutron energy of the analysis to a few MeV. For n- 12 C, new elastic and inelastic scattering data from Vanhoy support the results of the present analysis. More work is needed to extend the fit successfully above 6.5 MeV.