Python API

NDManager provides some python API to interact with your database.

In [1]: from ndmanager import get_endf6
   ...: get_endf6("endfb71", "n", "Pu239")
Out[1]: PosixPath('/Users/nlinden/.ndmanager/endf6/endfb71/n/Pu239.endf6')

A typical use for this would be for loading the ENDF6 tape into an OpenMC IncidentNeutron object:

In [1]: from ndmanager import get_endf6
   ...: from openmc.data import IncidentNeutron
   ...: tape = get_endf6("endfb8", "n", "Pu239")
   ...: n = IncidentNeutron.from_endf(tape)

You can also access the classes used to interact with the IAEA nuclear data service: IAEA,

IAEALibrary, and IAEASublibrary.

The IAEA acts as a dictionnary that maps library names or aliases to the corresponding IAEALibrary object, which maps sublibrary names (n for neutron data, decay for radioactive decay data, etc.) to an IAEASublibrary, which maps nuclide name to the tape’s URL.

You can initialize the database like so:

In [1]: from ndmanager import IAEA
   ...: iaea = IAEA()

If you have never used the ndf command or the IAEA class, initialization should take around a minute. The database is then cached into the ~/.config/ndmanager/IAEA_cache.json file and subsequent initialization should be near instantaneous. Using the IAEA is then fairly straightforward

In [1]: iaea["endfb8"]["n"]["Pu239"]

Returns the URL of the desired tape (tapes a compressed in a zip file on the website). To automatically download and extract the tape to an ENDF6 file, use the download_single method:

In [1]: iaea["endfb8"]["n"].download_single("Pu239", "./Pu239.endf6")