Adding atomdb data to quick factories

[marquezj]

Hi, I am trying to add new nuclides to with custom atomdb data, but I cannot find a proper solution. This is a workaround to add impurities or other minor isotopes, related to #177

For instance, let's say I want to add He8. If I try:

NC.load('freegas::He/He_is_He8/1perAa3;atomdb=He8:8u:0fm:1b:0b')

then I get NCBadInput: Invalid AtomDB specification (component "He8" is not a known element, isotope, or mixture). My understanding then is the atomdb data should be inside the cfg string for the factory, but I cannot find the proper syntax.

[tkittel]

You need to use:

NC.load('freegas::He/He8_8u_0fm_1b_0b/He_is_He8/1perAa3')

Anything you would normally put in the atomdb cfg-string parameter, you can put in the quick factory "name" part, but with underscores (the He_is_He8 is exactly such as line).

For reference valid atomdb lines are described in: https://github.com/mctools/ncrystal/wiki/NCMAT-format#the-atomdb-section

[marquezj]

Perfect. OpenMC can provide the atomic mass of the isotope and its free atom XS, which can be extracted from the 0K data. This allows to add the extra nuclides in the incoherent approximation (either as freegas or solid).