Problem 1429

Summary:	effective charge of ion
Product:	Geant4	Reporter:	michel.maire
Component:	processes/electromagnetic	Assignee:	Vladimir.Ivantchenko
Status:	RESOLVED MOVED
Severity:	normal
Priority:	P5
Version:	other
Hardware:	All
OS:	All

Description michel.maire 2013-01-20 11:43:03 CET

An ion created with Q=0 is deviated in magnetic field, even in vacuum.
 If ionIonisation process is desactivated, the trajectories look OK.
 
 The following macro, for N03, illustre the problem:

 # this macro can be executed at any time during an interactive session:
 # Idle> /control/execute magfield.mac 
 #
 /N03/det/setNbOfLayers 1
 /N03/det/setAbsMat Galactic
 /N03/det/setAbsThick 40 cm
 /N03/det/setGapMat Air
 /N03/det/setGapThick  0 cm
 /N03/det/setSizeYZ   40 cm
 #
 /N03/det/setField -5 tesla
 /N03/det/update
 #
 /vis/viewer/zoom 1.3
 #
 /gun/particle ion
 /gun/ion 8 16 0
 /gun/energy 500 MeV
 #
 /run/beamOn 20
 #
 /process/inactivate ionIoni
 /run/beamOn 20

Comment 1 Vladimir.Ivantchenko 2013-02-05 19:44:45 CET

Hello Michel,

This problem is expected in the default models of ion ionisation: G4BetheBlochModel and G4BraggIonModel. There are alternative models  G4BetheBlochIonGasModel and G4BraggIonGasModel which should be applied for transportation of ions in low-density media.

To address the problem of this report for default ion ionisation models an extra development should be carried out. This is planned for second part of 2013. Making simple modification of the current ion code would be dangerous due to possible side effects.

VI

Comment 2 Vladimir.Ivantchenko 2013-02-25 19:57:52 CET

This problem is moved to working plan of EM standard as new development in 2013 and have been included in JIRA system.

VI