Bug with old version of Geant Tracking System pions

Dear all,
i am unfortunately bound to use an old version of GEANT because i use CRESTA (Files · master · cosmicraysim / cresta · GitLab) .

What i have is basically described here in details, it’s exceptions while using QGSP_BERT_HP and BIC_HP. I am simulating muons and detecting a coincidence of muons and neutrons (muon-induced neutron imaging).

https://bugzilla-geant4.kek.jp/

Do you have any advice on how i can get around this issue without updating Geant?
I measure the muon when it’s incoming, before getting into the target, i need it to interact with the nuclei and produce neutrons, and detect the neutron back out of the target. I fear this exception is getting rid off too many events.

Hi @nancy_kurise_SA

Did you try using one of the physics lists that did not expose the problem for me? It looked like only some of electromagnetic options (EMY and EMZ) were affected, so e.g. FTFP_BER_EMX should work fine.

Best,
Simon

I am quite new to this so i am not sure how it would affect the model = which models i can use that are still gonna be representative and for what i need and not give wrong results (if i use not HP i get really bad values for thermal neutrons for example)