Numerical Precision

The energy grid on the input PENDF tape may have been produced by RECONR, or it may be the result of a previous BROADR run. In either case, most of the energy values will be given to seven significant figures using the standard 11-column ENDF format, e.g., 1.234567+1. It is possible that some of the input energies will use the nine-digit form, e.g., 1.23456789. All of the cross section values will use seven significant figures.

When BROADR determines its new union grid, all the "nodes" used as starting points for the relinearization can be represented with the seven-digit form. The new points in the grid are produced just as in RECONR, and it is possible that nine-digit energies may be required in some cases. However, broadening tends to smooth the cross sections, and the nine-digit energies will often disappear. All Doppler-broadened cross sections are reduced to seven significant figures on output.


23 January 2013 T-2 Nuclear Information Service