Gamma radiation from fission

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1

Hello,
Is it possible to extract from OpenMC the gamma radiation from fission? I want to use this as the gamma source in a shielding calculation.

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2

@Stepniac We don’t have a way of doing that right now. The only thing I could suggest is to look into our data files to pull out the gamma spectra from fission. Here’s an example with U235 from ENDF/B-VII.1:

In [1]: import openmc

In [2]: u235 = openmc.data.IncidentNeutron.from_hdf5('/opt/data/hdf5/endfb71_hdf5/U235.h5')

In [3]: fission = u235[18]

In [4]: fission.products
Out[4]: 
[<Product: neutron, emission=prompt, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: neutron, emission=delayed, yield=tabulated>,
 <Product: photon, emission=prompt, yield=tabulated>]

In [5]: photon = fission.products[-1]

In [6]: photon.distribution
Out[6]: [<openmc.data.uncorrelated.UncorrelatedAngleEnergy at 0x151ec02ff5b0>]

In [7]: photon.distribution[0]
Out[7]: <openmc.data.uncorrelated.UncorrelatedAngleEnergy at 0x151ec02ff5b0>

In [8]: energy_dist = photon.distribution[0].energy

In [9]: energy_dist
Out[9]: <openmc.data.energy_distribution.ContinuousTabular at 0x151ec02ff6a0>

In [10]: energy_dist.energy
Out[10]: array([1.e-05, 2.e+07])

In [11]: energy_dist.energy_out[0]
Out[11]: <openmc.stats.univariate.Tabular at 0x151ec02ff7f0>

In [12]: energy_dist.energy_out[0].x
Out[12]: 
array([      0.,   50000.,  100000.,  150000.,  163000.,  178000.,
        200000.,  212000.,  225000.,  245000.,  265000.,  300000.,
        325000.,  350000.,  365000.,  400000.,  430000.,  450000.,
        485000.,  500000.,  525000.,  545000.,  575000.,  605000.,
        625000.,  650000.,  670000.,  683000.,  700000.,  750000.,
        800000.,  900000., 1000000., 1100000., 1200000., 1250000.,
       1350000., 1500000., 1750000., 2000000., 2250000., 2500000.,
       2750000., 3000000., 3250000., 3500000., 3750000., 4000000.,
       4250000., 4500000., 4750000., 5000000., 5250000., 5500000.,
       5750000., 6000000., 6250000., 6500000., 6750000., 7000000.,
       7500000., 7750000., 8000000., 8100000.])

In [13]: energy_dist.energy_out[0].p
Out[13]: 
array([1.41741068e-07, 2.36735113e-07, 3.95393189e-07, 6.67564319e-07,
       7.10106340e-07, 6.12309293e-07, 8.63158413e-07, 1.10550053e-06,
       8.43338403e-07, 6.09406291e-07, 4.11009197e-07, 6.84580327e-07,
       8.17813391e-07, 1.03042049e-06, 1.06586051e-06, 9.39634449e-07,
       8.41837403e-07, 8.84379423e-07, 9.96390477e-07, 9.59554459e-07,
       8.24920395e-07, 7.32728350e-07, 8.75871419e-07, 9.53848456e-07,
       8.63158413e-07, 7.28524348e-07, 7.75271371e-07, 7.99395382e-07,
       7.18614344e-07, 6.97293334e-07, 6.63259317e-07, 5.10207244e-07,
       4.20918201e-07, 3.58556171e-07, 3.41539163e-07, 3.27425157e-07,
       2.82080135e-07, 2.01300096e-07, 1.28928062e-07, 9.34929447e-08,
       7.36732352e-08, 5.86583281e-08, 4.50448215e-08, 3.43341164e-08,
       2.48247119e-08, 1.97196094e-08, 1.56155075e-08, 1.27126061e-08,
       9.34929447e-09, 6.57654315e-09, 5.07504243e-09, 4.21419202e-09,
       3.55353170e-09, 3.02300145e-09, 2.58257124e-09, 2.17216104e-09,
       1.76175084e-09, 1.42141068e-09, 1.10109053e-09, 8.60856412e-10,
       4.20418201e-10, 1.20119057e-10, 1.00099048e-11, 0.00000000e+00])