Problem 147

Summary: unusually long step length with LowEnergyIonisation even with low cut
Product: Geant4 Reporter: rtascher
Component: processes/electromagnetic/lowenergyAssignee: Maria.Grazia.Pia
Status: RESOLVED INVALID    
Severity: normal    
Priority: P2    
Version: 2.0   
Hardware: Other   
OS: Other   

Description rtascher 2000-08-10 13:20:14 CEST
Look at step #61 of this excerpt of a trace. The step length is 11.1 mm  for a 7
MeV electron in water !!! This yields a huge 1.73 MeV energy deposit.
The cut was set to 0.5 mm.

*************************************************************************
* G4Track Information:   Particle = e-,   Track ID = 1,   Parent ID = 0
*************************************************************************

Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
NextVolume ProcName

     (...)
   57    -21.2     31.3     -110      8.82  0.00314     15.5       987 World
Physical           LowEnergyIoni
   58    -16.1     31.6     -111      8.82 0.000735     5.18       992 World
Physical           LowEnergyIoni
   59 1.27e-14     32.7     -113      8.82  0.00339     16.3  1.01e+03 TargetPV
Transportation
   60    0.183     32.7     -113      8.78   0.0324    0.184  1.01e+03 TargetPV
LowEnBrem
   61     11.1     31.6     -113      7.05     1.73     11.1  1.02e+03 TargetPV
LowEnergyIoni
   62     19.2     34.5     -113      5.59     1.46     8.88  1.03e+03 TargetPV
LowEnergyIoni
   63     25.9     36.7     -113      4.49      1.1     7.02  1.04e+03 TargetPV
LowEnergyIoni
Comment 1 pia 2000-10-04 04:18:59 CEST
This was identified as a not to be a problem; the energy deposit is consistent
with what one expects. As to the step length, indications were conveyed to the
user as to the usage of Geant4 in microdosimetry applications.
Sorry for this late reply; the problem was indeed handled with the user time
ago.