BUG: mcxtrace: fluorescence

[farhi]

Weird behavior of fluorescence samples for McXtrace.

• Unstable SOLEIL_LUCIA
• SPLIT does not reproduce non-SPLIT results

Two attempts to solve have been started:

• DO NOT MERGE (Attempts to stabilize fluo) #2037
• https://github.com/farhi/McCode/tree/4-mcxtrace-fluo-fix-again

which do improve results, but are not sufficient.

[farhi]

The issues may be related to Bragg_crystal that shows large intensity variations.
More checks are also probably required regarding SPLIT.

[farhi]

Seems there is not special to do at the Bragg_crystal. It is safe and stable.
I have tuned the double monochromator to the undulator emission peak, and increased the fluorescence detector size. Result now seems stable on SOLEIL_LUCIA.

[farhi]

Many tests are now failing ⚠️ Will have a look on Tuesday...

• https://new-nightly.mcxtrace.org/2025-05-31_output.html

[farhi]

Just pushed a new set of example test values fixes in https://github.com/farhi/McCode/tree/7-mcxtrace-fix-examples
Also made some tests faster to execute so that our test suite can be obtained in less time/cpu.