Reaction extract
The natural function of the FISPACT-II collapse is to reduce the full multi-group cross section data and a user-supplied incident particle spectrum into one-group effective cross sections to obtain reaction rates. For many reasons it may be desirable to have the full energy-dependent reaction rates and energy-dependent uncertainties available for visualisation and/or checking purposes.
A separate utility programme, extract_xs_endf allows the user to specify specific reactions and extract a variety of data on the energy-dependant reaction rates. It takes in the following arguments:
- fileroot name for the output, which will generate fileroot.out and fileroot.log
- projectile, given as a letter from the choices of: n, p, d, a, g
- energy group of the nuclear data, taken from the possible 1102, 709 or 162 group structures
- parent nuclide, which is the target nuclide for the reaction
- the mt number of the reaction, which must be drawn from the allowable values in the FISPACT-II mt list
- daughter nuclide, which is the product of the specific reaction - note that isomers are defined in the usual way, e.g. In116m
- [optional] the name of the files file (default files)
The files file must include a nuclide index file ind_nuc, incident particle spectrum fluxes file and the directory for the cross section data xs_endf, for example:
# Index of nuclides to be included ind_nuc /path/to/fispact/ENDFdata/TENDL2015data/tendl15_decay12_index # Incident particle spectrum fluxes /some/data/directory/my_fluxes # Library cross section data xs_endf /path/to/fispact/ENDFdata/TENDL2015data/tal2015-n/gxs-709
An example execution would be:
extract_xs_endf U238_capture n 709 U238 102 U239
which would generate U238_capture.out with an eight column output including:
- En-low = lower energy of the group
- En-high = higher energy of the group
- flux = group flux(i), as in the flux file
- flux-unc = 0.000000E+00 (this feature is turned off in distributed versions)
- gxs = group cross section, as in the TENDL file
- gxs_unc = mapped variance one sigma of the group cross section, in %
- greac-rate= flux(i)*gxs(i)/flux(1:709)
- cum-rate = incremental sum of the greaction-rates, in %