Manually turn number of atoms into at/b-cm

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1

So i did loads of calculations and have too much results which take too long to rerun the simulations and turn the number of atoms to at/b-cm by code so because i have all teh data in excel i was wondering what the simple equation was for this?

Many thanks

2

If you have the volume of the relevant region in cm³, then to go from atoms to atom/b-cm, you should divide by the volume and multiply by 1e-24. since 1 b = 1e-24 cm.

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3

Thank you. I eventually managed figured it out. Saved me lots of time. Really need to learn to use pyhton/Linux properly for file manipulation

4

for this problem i do not have the volume but the density. Am I ok to just divide by ten then multiple by 1e-24 to turn it to b-cm?

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5

If you have a material defined in the Python API, you can use the Material.get_nuclide_atom_densities method to get the atom density of each constituent nuclide in atom/b-cm:

In [1]: import openmc                                                                                    

In [2]: uo2 = openmc.Material()                                                                          

In [3]: uo2.set_density('g/cm3', 10.0)                                                                   

In [4]: uo2.add_nuclide('U234', 9.1361e-6)                                                               

In [5]: uo2.add_nuclide('U235', 9.3472e-4)                                                               

In [6]: uo2.add_nuclide('U238', 2.1523e-2)                                                               

In [7]: uo2.add_nuclide('O16', 4.495e-2)                                                                 

In [8]: for nuc, atombcm in uo2.get_nuclide_atom_densities().values(): 
   ...:     print(f'{nuc} = {atombcm:.4e} atom/b-cm') 
   ...:                                                                                                  
U234 = 9.0725e-06 atom/b-cm
U235 = 9.2821e-04 atom/b-cm
U238 = 2.1373e-02 atom/b-cm
O16 = 4.4637e-02 atom/b-cm
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