Microscopic Scattering Matrix

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Microscopic Scattering Matrix

Post by cgentry7 » Thu Dec 03, 2015 6:19 pm

I just wanted to confirm, but SERPENT 2 still cannot produce a microscopic scattering matrix, correct?


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Jaakko Leppänen
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Re: Microscopic Scattering Matrix

Post by Jaakko Leppänen » Thu Dec 03, 2015 8:15 pm

That is correct. The problem is that the cross section data does not include the double-differential scattering cross sections, but rather total reaction cross sections and scattering laws from which the energy and scattering angle of secondary neutrons are sampled.

The only way to obtain scattering matrices is to use an analog esimator for the group-to-group scattering rate (counting the number of reactions). This works well for macroscopic cross sections, but not microscopic, because the reaction rates for individual nuclides can be negligibly small.

It would be possible to sample group-to-group scattering reactions just to get the estimators for the scattering matrices. This is on my TODO-list.
- Jaakko

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