Problem 1753

Summary:	Energy non-conservation in the G4HadronElasticProcess
Product:	Geant4	Reporter:	inguimbe
Component:	processes/hadronic	Assignee:	Vladimir.Ivantchenko
Status:	RESOLVED WONTFIX
Severity:	normal	CC:	Alberto.Ribon
Priority:	P5
Version:	9.6
Hardware:	PC
OS:	Windows

Description inguimbe 2015-06-04 09:49:03 CEST

We are using the G4HadronElasticProcess in order to generate, with incident protons, Silicon recoils in a silicon target. In the following, we present some informations listed at each step of the UserSteppingAction. At each step, the creator process, the current process, and the energy balance is shown. We do not understand these results because the energy conservation law seems not to be met.

a 63 incident MeV proton produces a hadron elastic interaction. The corresponding energy loss is 0.254879 MeV. At this step the total deposited energy is equal to 0.000117664 MeV.

But the recoil energy of the produced silicon ion is equal to 0.271833 MeV. That represents 6.28 % more than the expected value (0.254879-0.000117664).

We get the same result for all the produced recoil ion (~6.28 % difference).


As you can see we have used the G4XWrapperProcess in order to bias the G4hadronElasticProcess cross section (X-hadElastic) with the GEANT4.9.6 p03 version.

We do not understand this result and where does come the problem !


Does someone could bring us some clarifications ?
Thank you in advance.

Christophe Inguimbert


Creator Process ----	PostProcess	X-hadElastic
ParentID	0	TrackID	1	
proton	
Pre kin	63, Post kin	62.7451	
deltaE	-0.254879	
Deposited Energy 0.000117664
Non Ioniz DE	0


Creator	Process X-hadElastic	PostProcess	ionIoni	
ParentID	1	TrackID	2
Si28[0.0]	
Pre kin	0.271833, Post	kin	0.11474
deltaE	-0.157093	
Deposited Energy 0.157093
Non Ioniz DE	0.0230247

Comment 1 Vladimir.Ivantchenko 2015-07-29 12:54:17 CEST

Hello,

It is not obvious how to understand the problem. There are two variants. You attach to this bug report a tar file with your application and instructions how to reproduce the problem. This may not be easy if the application depends on your local environment - it may not work in our environment.

Alterntive way, the most convinient to us, would be to reproduced in a simple setup. For that take $G4INSTALL/examples/extended/hadronic/Hadr00 , define target as G4_Si, projectile proton with energy 63 MeV, use /tracking/verbose 2, select one of Physics Lists (default if FTFP_BERT) and in few events you should see the effect. If the bug will be confirm, it is enough to attach macro file to the bug report.

VI

Comment 2 Vladimir.Ivantchenko 2015-12-11 15:09:42 CET

Hello,

Due to the situation that additional information is not provided we cannot follow this problem. The advice would be to switch to newer releases of Geant4 10.1p02 or 10.2.

This bug report will be closed.

VI