Hi Experts,
I am trying to define the current that leaves an irradiated pebble surface. I have the isotope composition and can get the decay energies to sample in the pebble by using the function:
get_decay_photon_energy(clip_tolerance: float = 1e-06, units: str = 'Bq', volume: float | None = None)→
I have also figured from other post on the forum that its not straightforward to bias the gamma emissions so they only travel outward from the core of the pebble through the graphite shell and out the pebble surface (I don’t know if this has changed).
The main issue I am experiencing now is being able to get the gamma or photon current leaving the core of the pebble and out of the graphite surface. At the moment I am applying the SurfaceFilter and CellFromFilter, my hope is that these would allow me get the outwards facing current and not the net current at the pebble surface. So far this is what I have:
bins = np.linspace(0.0, 1.5E6, 1025).tolist()
energy_filter = openmc.EnergyFilter(bins) # eV bins
particle_filter = openmc.ParticleFilter(['photon'])
surface_filter = openmc.SurfaceFilter(list(surface_ids))
cell_from_filter = openmc.CellFromFilter(list(cell_ids))
gamma_tally = openmc.Tally(name='gamma_current_tally')
gamma_tally.filters = [surface_filter, cell_from_filter, particle_filter, energy_filter]
gamma_tally.scores = ['current']
My plan was to filter the dataframe in the StatePoint file to extract the current of gammas leaving the graphite shell (or cell) and crossing the pebble surface. However, when I check the tally of gamma energies crossing the surface, they bins are all zero. I then decided to generate a flux mesh on my geometry to see if where I am sampling gammas is accurate and there seems to be gamma where I specify them. I am sampling closer to the edge of the pebble core although I know the emissions are still isotropic. Based on what I see on the generated slice (attached), there is some flux of photons on the pebble surface that should give me some current hits. So I would like to ask if there is any one who has some suggestions on how to address this issue. Thanks in advance.
