Problem 1354 - Electron nuclear crash at very high energies (>30 TeV)
Summary: Electron nuclear crash at very high energies (>30 TeV)
Status: CLOSED FIXED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/hadronic/models/chiral_inv_phase_space (show other problems)
Version: other
Hardware: All All
: P5 normal
Assignee: Andrea Dotti
URL:
Depends on:
Blocks:
 
Reported: 2012-09-17 12:12 CEST by Andrea Dotti
Modified: 2012-09-28 14:25 CEST (History)
1 user (show)

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Description Andrea Dotti 2012-09-17 12:12:44 CEST 
A thread in user forum (#723) reports an issue with QGSP_BERT physics list for very high energy interactions of electrons with nuclei.
The problem can be summarized as follows:
The G4ElctroNuclearReaction constructor reads:
 63   G4ElectroNuclearReaction():G4HadronicInteraction("CHIPSElectroNuclear")
 64   {
 65     SetMinEnergy(0*GeV);
 66     SetMaxEnergy(30*TeV);
But line 75 reads:
 75     theHEModel->SetMaxEnergy(100*TeV);
 A user was simulating 100 TeV proton interactions and received the following exception:

*** G4Exception : had005
      issued by : G4HadronicProcess::PostStepDoIt
Target element Hydrogen Z= 1 A= 1
Unrecoverable error in the method ChooseHadronicInteraction of ElectroNuclear
TrackID= 1956 ParentID= 1783 e-
Ekin(GeV)= 56475.1; direction= (1,-4.94155e-06,1.46426e-05)
Position(mm)= (8.90224e 10,-525110,1.56947e 06); material Hydrogen
PhysicalVolume <World>
 No HadronicInteraction found out

*** Fatal Exception *** core dump ***
-------- EEEE -------- G4Exception-END --------- EEEE -------


*** G4Exception: Aborting execution ***

The user has been suggested to test a simple fix:
change line 66 to:
 66     SetMaxEnergy(100*TeV);
Propose to wait for feedback before implementing fix.
The problem should affect several physics lists in both supported versions of G4: 9.4 and 9.5

Andrea
Comment 1 Andrea Dotti 2012-09-21 16:29:27 CEST 
Hello,
we have received feedback from user. The proposed solution actually works.
See thread:
http://hypernews.slac.stanford.edu/HyperNews/geant4/get/phys-list/723.html
I'll propose a tag to fix this issue.
Comment 2 dennis.herbert.wright 2012-09-26 02:34:51 CEST 
Fix was made in G4ElectroNuclearReaction. Will appear in Geant4 9.6 and perhaps in a patch of 9.5.