NUDEX captures giving gammas only for one isotope

Physics Processes, Models and Cross Sections
1

Hello all,

I’m using the new nudex option to produce the gamma cascades from neutron capture on liquid argon. It works nicely but it only produce neutron capture on Ar-40, while we expect a few captures on other isotopes (Ar-36 Ar38).
Any idea of what could be the problem? There are interaction of neutrons with Ar36 (hadElastic) but I have 0 captures on this isotope, 100% of the captures are onAr-40. This was the case also without nudex when I updated to Geant4.11.3, but was fixed using the ENDF/B-VIII.0 library for the $G4NEUTRONHPDATA. Now this problem arises only when I use nudex. Any idea of what could be the problem? and how to fix it?
Best regards,
Luis

_Geant4 Version: 11.3
_Operating System: linux
_Compiler/Version: gcc
_CMake Version: cmake/3.29.2

2

Extra info: it seems it’s related to the physics list: QGSP_BERT_HP
Which does produce only neutron capture on Ar-40
Other physics lists like FTFP_BERT_HPT or Shielding does produce n capture on different argon isotopes. However nudex can only work with QGSP_BERT_HP
Can some option make it possible to use nudex with the other physics lists?
So a bug in QGSP_BERT_HP?