Spectra tally on cells

[shimwell]

Proposed changes

This adds the ability to tally neutron and photon spectra on the cells.

When defining a model we now have a few cell tallies that are supported (heating, flux, TBR, spectra).

The next tally to add is fast flux which is can be done in a very similar way to spectra but with a two group energy bin and then deletion of the values in the first (thermal) group. Admittedly this is probably not the most efficient way to implement such a tally but good to start somewhere.

Anyway the spectra is by default 709 CCFE energy group so perhaps this should also a user controllable an option in the future.

my_model = paramak.NeutronicsModel(
    geometry=self.my_shape,
    source=self.source,
    materials={'center_column_shield_mat': mat},
    cell_tallies=['heating', 'flux', 'TBR', 'spectra'],
    simulation_batches=2,
    simulation_particles_per_batch=2
)

Note the new keyword 'spectra'

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Code refactoring
• Documentation Update (if none of the other choices apply)
• New tests

Checklist

• Pep8 applied
• Unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[shimwell]

This is just failing on the sweep tasks