Problem 1182

Summary: Fermi breakup throws exception as a result of K0L inelastic interaction
Product: Geant4 Reporter: John Apostolakis <John.Apostolakis>
Component: processes/hadronic/models/de_excitation/fermi_breakupAssignee: Jose Manuel Quesada <quesada>
Status: RESOLVED FIXED    
Severity: normal CC: andy.buckley, dennis.herbert.wright, Vladimir.Ivantchenko, zmarshal
Priority: P2    
Version: 9.4   
Hardware: PC   
OS: Linux   
URL: http://voatlas21.cern.ch/monitor/logs/2c0f42d1-d740-42e7-b4e4-d08423f71e42/tarball_PandaJob_1213865792_BNL_ATLAS_1/athena_stdout.txt

Description John Apostolakis 2011-03-29 13:35:53 CEST
ATLAS reported that every 1 per 1000 run of their latest test production reported the following exception:

In src/G4FermiPhaseSpaceDecay.cc, line 77:
===> G4FermiPhaseSpaceDecay::KopylovNBodyDecay: Error sampling fragments momenta!!
Call for FTFP
Target element Aluminium  Z= 13  A= 27
Unrecoverable error in the method ApplyYourself of KaonZeroLInelastic
TrackID= 260  ParentID= 0  kaon0L
Ekin(GeV)= 53.751093784752;  direction= (0.010560888333136,-0.0059938301376881,0.99992626810075)
Position(mm)= (60.707282117659,-33.246284100834,5779.1063445055); material Aluminium
PhysicalVolume  <LArMgr::LAr::Endcap::Cryostat::Cylinder::Mixed>

*** G4Exception : 007
     issued by : G4HadronicProcess
PostStepDoIt failed.
*** Fatal Exception *** core dump ***
Comment 1 John Apostolakis 2011-03-29 13:47:05 CEST
The physics list used was FTFP_BERT.

The URL is updated with the output log of the file - in case additional information could be gleaned.  A first inspection does not find more useful information in this file.
NOTE: this link/file will have a limited lifetime (length tbc).
Comment 2 John Apostolakis 2011-04-11 13:33:24 CEST
Have not been able to reproduce this problem.  Ran 125 million interactions, at this and nearby energies. No crashes found.

Code inspection is ongoing.
Comment 3 Jose Manuel Quesada 2011-04-12 00:59:07 CEST
Vladimir   has tagged the fix for G4FermiPhaseSpace and it is under stt testing
Comment 4 Vladimir.Ivantchenko 2011-08-15 18:15:07 CEST
The protection is added to the code the exception should not happen anymore. The fixed code is available with Geant4 9.5beta. The problem should be closed. 

VI