|
This file says to run RECONR on MAT1050 with a reconstruction
tolerance of .001 (.1%). The output will be on tape21. The
title on the Tape ID card will be "exercise 3," and the single
information line in the output file will say "94-Pu-238." The
output is written on tape21.
Run the NJOY job with this input file.
Examine the file called "output" to see the new messages from
BROADR. Note that 475 points were added for linearization
even before resonance reconstruction began. The resolved
resonance range is seen to run from 1 to 200 eV, and an additional
6215 points were added to represent the detailed shapes of the
resonances. This particular evaluation uses the single-level
Breit-Wigner resonance representation, which can produce negative
elastic scattering cross sections, and the message from
subroutine EMERGE indicates that that happened here.
Examine the file called "tape21" to see what the new
resonance PENDF tape looks like.
- Check MF=3, MT=2 (elastic scattering). Find the lower limit
of the resolved resonance range. What happens to the
cross section there?
- Find the center of the lowest resonance at 2.855 eV. Note
that the peak is at higher energies and that there is an
interference dip at lower energies.
- Check the 18.56 eV resonance. Note the place where the
interference minimum went negative and was replaced by a
small number. This was one of the sources of the message
from EMERGE. Note that the energy grid went to a
precision of nine significant digits temporarily.
- Check MF=3, MT=102 (radiative capture). Where is the peak
of the lowest resonance in this case?
- Check MF=3, MT=18 (fission cross section). Where is the peak
of the lowest resonance in this case?
- Check MF=3, MT=1 (total cross section). Note that it is
dominated by the capture component.
- Go back to the beginning of tape21 and look at File 1. Note
the directory of sections--only Files 1, 2, and 3 are present.
You can also see the Tape ID and comment lines from the input
deck, and the third card shows a temperature of 0K and a
reconstruction tolerance of 1e-3.
- Finally, scan down to MF2, MT152. This is a special NJOY
section giving the infinitely dilute unresolved resonance
range cross section. Note that the unresolved range runs
from 200 eV to 10 keV.
Now, modify in3 to contain the following lines to enable the
cross sections from tape21 to be plotted:
|