Passing ace to make_ace is not supported. Use acer instead.
The acer argument now signals if the acer njoy module should
be run and where to save the output file. xsdir defaults to
None now, rather than "xsdir". This change allows the xsdir
file to be written to the same directory as acer, or a user
supplied location potentially separate from ace file.
This reverts d81aaeca9 and 81c625928 in the following ways.
Fission heating data, MT318, is pulled from the heatr file
produced when running NJOY. Reaction data that is potentially
temperature dependent is set onto the IncidentNeutron object
by scaling MT318 by the ratio of the fission cross section
used in HEATR and other fission cross sections stored on the
object. This produces potentially many MT318 fission heating
KERMA coefficients on the nuclide.
The fission-less heating coefficient, MT999, if computed by
subtracting MT318 from MT301, total heating coefficients. This
reaction is marked as redundant, as it can easily be reconstructed.
MT318 is allowed to be written to the HDF5 file, while 999 is not.
When reading back in the library, MT999 is rebuilt in exactly
the same manner.
The test_heating test in tests/unit_tests/test_data_neutron.py
has been updated given the changes in this commit.
It is worth noting that the heating coefficients computed in
NJOY only contain prompt neutrons, as
k_{i,j}(E) = sigma_{i,j}(E) * (E + Q - \bar{E})
where k_{i,j} is the kerma coefficient for reaction j of material
i, sigma_{i,j} is the corresponding reaction cross section, E
is the energy of incident particle, Q is the mass-difference
Q value, and \bar{E} is the average energy of secondary particles.
Source: NJOY16 Manual on HEATR
IncidentNeutron.from_ace now computes the fission heating
and a fission-less heating coefficient. The fission heating
is the product of the heating number and the fission cross
section, and stored as MT318.
The fission-less heating is the heating from all reactions
except fission, computed as heating_number * (total_xs - fission_xs).
The MT number for this is taken to be 999 as a temporary value.
A test is added for Am244 in test_data_neutron.py to examine the
new heating values
