Adapt transformation function for PhotoPairInterpolant #383
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…ables to increase numerical efficiency. Add constructor to use Integral instead if Interpolation Crosssections for secondaries::PhotoPairProductionInterpolant classes
|
Attention: For whatever reasons, tests are having problems at the moment... |
Jean1995
commented
Dec 11, 2023
| @@ -126,7 +126,7 @@ double crosssection::PhotoPairKochMotz::DifferentialCrossSection( | |||
| }; | |||
| auto dNdx_nocorrection = i.Integrate(limits.v_min, limits.v_max, integrand, 3); | |||
| auto A = interpolant_->InterpolateArray(comp.GetNucCharge(), energy) / dNdx_nocorrection; | |||
| return A * DifferentialCrossSectionWithoutA(p, comp, energy, v); | |||
| return std::max(A * DifferentialCrossSectionWithoutA(p, comp, energy, v), 0.); | |||
There was a problem hiding this comment.
This actually requires re-calculation of the A factors! Otherwise, we get a problem...
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is an attempt at solving issue #382
The first approach that brought better results was to adapt the transformation function in
xfor the interpolation tables.At the moment, the nodes in
xin the interpolation tables are distributed linearly in the logarithmic room. However, as x is always between 0 and 1, and symmetric around 0.5, this transformation rule is not really suitable here.Therefore, I have changed the notes to be linear in x.
For large energies, this significantly improves the results. For small energies, there are still some problems, although the distribution at least looks more symmetric now.
I have also implemented functions to use the CrossSectionIntegral instead of CrossSectionInterpol functions for the secondary calculators of PhotoPairProduction, see #382, so I am able to make comparisons.
Improvements
Here are the sampled distributions for the current master and with this PR.
Note that the computation time stays identical.
1e5 MeV Photons:
Old distributions:
New distributions:
10 MeV photons:
Old distributions:
New distributions:
2 MeV photons:
Here one can still see a significant deviation between Integral and Interpol.
Old distributions:
New distributions: