5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM
RESEND expects its
input to be a standard mode BCD ENDF file (Version II/III). Since
the output is also a standard mode BCD ENDF file, the program is
limited by the six significant figure accuracy inherent in the
ENDF formats. (If the cross section has been calculated at two
points so close in energy that only their least significant
figures differ, that interval is assumed to have converged, even
if other convergence criteria may not be satisfied.) In the
unresolved range the cross sections have been averaged over a
Porter-Thomas distribution. In some regions the calculated
resonance cross sections may be negative. In such cases the
standard convergence criterion would cause an unnecessarily large
number of points to be produced in the region where the cross
section becomes zero. For this reason an additional input
convergence criterion (AVERR) may be used. If the absolute value
of the cross section at both ends of an interval is determined to
be less than AVERR then the interval is assumed to have converged.
There are no limitations on the total number of points generated.
The present ENDF (Version II/III) formats restrict the total
number of points that can be given for a reaction type to 5000.
ADLER can handle resonance data up to a maximum of 10 isotopes
with a total number of 500 resonances. The code assumes that the
resolved resonance parameters are given for one energy range which
is the same for all the isotopes of an element. The mesh points
at which the cross sections are calculated can be varied. Since
the calculated data are not stored, an increase in the number of
mesh points does not conflict with any storage requirement.