Threshold Displacement Energy for Different Materials

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1

Hi all, had a question regarding the use of the threshold displacement energy used for DPA calculation according to the NRT-DPA model. I am not sure where this value of 40ev is coming from for the material used, how it differs for other materials, what it measures, and how it is calculated. Say I want to do this calculation for other materials like Titanium Hydride, Stainless steel, and borated steel, where could I obtain the specific values for them? It has been used in @Shimwell’s neutronics workshop to calculate the displacement per source neutron -


print('Damage energy deposited per source neutron = ', damage_energy_in_ev, 'eV\n')

print('Two times the threshold energy of 40eV is needed to displace an atom')
displacements_per_source_neutron = damage_energy_in_ev / (2*40)
print('Displacements per source neutron = ', displacements_per_source_neutron, '\n')```
2

Hi Anay,

You can find libraries and tables for this kind of data (displacement energy). It depends on the element/lattice/etc
Here’s an example
https://www.sciencedirect.com/science/article/pii/S0022311520304670
Table 1, 40 eV for iron, 69 eV for Carbon.

In my experience you use DPA cross-sections to evaluate material DPA in your neutronics code. The displacement energy figures in the evaluation/generation of the DPA cross-section

https://www-nds.iaea.org/CRPdpa/

https://www.sciencedirect.com/science/article/pii/S173857331830370X

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It would be great to improve that example in the neutronics workshop

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I have incorporated a couple of lines explaining the NRT assumption to this workshop when I showed it to my colleagues. Happy to share it :slight_smile: but don’t know how to insert jupyter notebook parts here.

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Nice, feel free to post a screenshot and i can update the workshop. If you are super keen the a PR to the workshop would be ideal. This is better as it would give you credit for the improvements in the git commits

1 Like
6

Great proposal, let me try to propose a Pull Request then :slight_smile: