cannot use same custom defined material for different components

[billingsley-john]

I have been using the NMM to assign custom materials to reactor components. I have noticed that the same custom material cannot be assigned to several different material tags.

E.g.

my_material = nmm.Material()

my_model = p.NeutronicsModel(
    materials = {
            "material_tag_1": my_material,
            "material_tag_2": my_material
    }
)

Only material_tag_1 is entered into the materials.xml file, resulting in a simulation error as the material for material_tag_2 cannot be found.

E.g.

<materials>
    <material id="X" name="material_tag_1">
        <density and nuclides>
    </material>
</materials>

This means that each material for each material_tag must be defined separately, even if the same material is used for several material tags

[billingsley-john]

(On develop branch)

[shimwell]

Ah yes sorry about this,

The underlying reason is because the tallies are linked to a specific material and the materials are used to identify each shape.

https://github.com/ukaea/paramak/blob/d477a7a048a7f3f209e2ba4a5ba0b815700ffbc6/paramak/parametric_neutronics/neutronics_model.py#L584

I hope to move it to volume based identification in the future but this is a core change to the assignment and reading of tallies.

Currently the work around is to make another material which is the same but a different object

[shimwell]

This is related to https://github.com/ukaea/paramak/issues/816