Update Reaction Data

It is possible to update reaction data from another XML file. This cookbook demonstrates how to do that using the fixed neutron abundance calculation.

First, prepare the network code as described in the Specify Abundances cookbook. Now run the network calculation:

$ ./single_zone_network @specific_species.rsp --output_xml out_sp.xml

Now rerun the calculation with updated data for the \(n + ^{56}{\rm Fe} \to ^{57}{\rm Fe} + \gamma\) reaction. Those new data will be from a Talys calculation. Create the new XML data by following the instructions at OSF. The resulting new.xml has the Talys reaction data.

It is a good idea first to compare the new rate to that computed from the data in the original XML file. This can be done with the python code compare_rates.py, which you can download with the command:

$ curl -o compare_rates.py -J -L https://osf.io/aewqz/download

The resulting file looks like this.

Now run the network calculation with the new data. To do so, use the --extra_reac_xml option:

$ ./single_zone_network @specific_species.rsp --output_xml out_sp_mod.xml --extra_reac_xml new.xml

The network code parses in new.xml after the network data and overwrites any reaction data from the original network file with those from the extra reaction XML file. Regarding this point, the network code stores reactions as a string. This means the order of the reactants and products is import. If data for the capture reaction are stored such that the network code would generate the string \(n + ^{56}{\rm Fe} \to ^{57}{\rm Fe} + \gamma\) for the original data and \(^{56}{\rm Fe} + n \to ^{57}{\rm Fe} + \gamma\) for the new data, the code will consider these as separate reactions, and the --extra_reac_xml option will cause the code to include both sets of data in the calculation.

Once the calculation is done, you can compare the results by typing in Python:

>>> import wnutils.multi_xml as mx
>>> xmls = mx.Multi_Xml(['out_sp.xml', 'out_sp_mod.xml'])
>>> p_params = [{'label': 'Reference'}, {'label': 'Talys'}]
>>> xmls.plot_mass_fraction_vs_property('time', 'fe58', xlim = [0, 1000], xfactor = 3.15e7, use_latex_names=True, xlabel = 'time (yr)', plotParams = p_params)

The resulting file shows that the faster capture rate on \(^{56}{\rm Fe}\) causes the mass fraction of \(^{58}{\rm Fe}\) to peak earlier in time and at a higher level.