Problem 639 - charged particle haotic tracing
Summary: charged particle haotic tracing
Status: RESOLVED INVALID
Alias: None
Product: Geant4
Classification: Unclassified
Component: tracking (show other problems)
Version: other
Hardware: PC Linux
: P2 normal
Assignee: Katsuya.Amako
URL: ~/public_html/Geant4_problems/6GeVpro...
Depends on:
Blocks:
 
Reported: 2004-07-01 13:14 CEST by tumakov
Modified: 2004-07-02 03:48 CEST (History)
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Description tumakov 2004-07-01 13:14:18 CEST 
Could somebody suggest me what happend with particle tracing in Geant4.6.2 ?
With 4.6.1 everything works fine, but in new version
instead of straight track I have a haotic particle movement even
in pumped air vacuum.

(I think neutrons are traced correctly)

Should I set some new environmental variables?
What was changed?

The figure in the link shows the trajectory of Ekin=6GeV proton in the vacuum.

               Regards, Vladimir Tumakov
Comment 1 tumakov 2004-07-01 13:18:59 CEST 
corrected reference to figure
http://meco.ps.uci.edu/~tumakov/Geant4_problems/6GeVproton_haotic_movement.eps
Comment 2 tumakov 2004-07-01 13:20:59 CEST 
corrected reference to figure
http://meco.ps.uci.edu/~tumakov/Geant4_problems/haotic/6GeVproton_haotic_movement.eps
Comment 4 Katsuya.Amako 2004-07-02 03:48:59 CEST 
Based on the hadronic PhysicsList code provided in geant4.6.2/examples/novice/
N04/src/ExN04HadronPhysics.cc, I tested protons of Ekin=6GeV with a simple box
geometry. For material air, water and vacuum were tested. I cound't reproduce
the spectacular (chaotic!!) event you found. Both Geant4.6.1 and 6.2 give
reasonable results with exactly the same test code.

Therefore it is not a problem in the component of 'tracking'. It may be a
problem in your application code - for example in your PhysicsList. If you
found a problem related to PhyiscsList, please report to process/hadronic.