Problem 637

Summary: Decay of isotope causing G4Exception
Product: Geant4 Reporter: drw
Component: processes/electromagnetic/lowenergyAssignee: alfonso.mantero
Status: RESOLVED FIXED    
Severity: normal    
Priority: P2    
Version: 6.1   
Hardware: PC   
OS: Linux   

Description drw 2004-06-21 06:54:36 CEST
I am simulating the activation, and subsequent decay, of a structure. As a
results of proton flux I get a Be7 isotope, which will decay via electron
capture. This capture causes this error:

* G4Track Information:   Particle = Be7[0.0],   Track ID = 5905,   Parent ID = 154
*********************************************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
NextVolume ProcName
    0     -938    -22.4 1.04e+03      4.67        0        0         0
SPIMidVetoBGOa initStep
    1     -938    -22.4 1.04e+03      1.58     3.09   0.0829    0.0829
SPIMidVetoBGOa hIoni
    2     -938    -22.4 1.04e+03         0     1.58   0.0199     0.103
SPIMidVetoBGOa hIoni
G4AtomicTransitionManager: Z not found

*** G4Exception: Aborting execution ***

The problem, I think, is with the transition of the electron from the higher
levels to the K-shell, as the problem is with the G4AtomicTransitionManager.
Looking in the data files (G4EMLOW2.2) there is no Auger electron data for
Beryllium, and looking at a Table of Isotopes there is a 10% chance of getting
an Auger electron during the Be7 decay. Maybe there could be a conflict in the
data tables? Just an idea.

Thanks
Dave Willis.
Comment 1 alfonso.mantero 2004-06-25 08:25:59 CEST
Well, Auger and Fluorescence are (at the moment) simulated only for elements
with 6<Z<100, so Berillium (Z=4) cannot generate fluorescence or Auger. However,
a local energy deposit should take place and the simulation should continue
without fluo or Auger generation. Bug is under study and will be solved shortly.
Comment 2 Luciano Pandola 2005-03-10 01:21:59 CET
Since 7Be decays via EC, G4RadioactiveDecay() triggers the generation of the
corresponding K alpha de-excitation through the DeexitationManager. The bug was
in G4RadioactiveDecay() (no control on Z, which has to be > 5 because of the
G4EMLOW2.2 database); this has been fixed in Geant4 7.0 (see Release Notes at
http://geant4.cern.ch/geant4/source/ReleaseNotes4.7.0.html)