Problem 1446 - BinaryLightIon many years bug
Summary: BinaryLightIon many years bug
Status: ASSIGNED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/hadronic/models/binary_cascade (show other problems)
Version: 9.6
Hardware: All Linux
: P5 enhancement
Assignee: Gunter.Folger
URL:
Depends on:
Blocks:
 
Reported: 2013-02-20 22:09 CET by Ivantchenko A.
Modified: 2019-03-11 18:11 CET (History)
1 user (show)

See Also:

Attachments
g4.9.6.ref02 test30 production (19.70 KB, image/gif)
2013-02-20 22:09 CET, Ivantchenko A. 		Details
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this problem.
Description Ivantchenko A. 2013-02-20 22:09:40 CET 
Created attachment 205 [details]
g4.9.6.ref02 test30 production

Please see attachment. already 2 or 3 releases we see this bug  in BICion  at 135 MeV/Nuc, at forward angles, typically He4 or C12 beams.
May be somebody can solve it ?
No QMD, no INCL (bad model for ions) do not have this problem, but Abrasion also has it.

regards,
Comment 1 Gunter.Folger 2013-02-21 18:06:15 CET 
Will need to look into this.
Do you observe similar peaks at other, higher, energies?
Comment 2 Ivantchenko A. 2013-02-21 19:37:45 CET 
This problem for BinaryLightIon is seen mainly for thin targets, 135 MeV/Nuc,
He4 beam (or few C12, Ne20), targets are different. At higher energies 290 MeV/Nuc it is very small, at 400 MeV/Nuc it dissapeares.

Sorry for publishing it as bug report - it is actually model property. Please see here - http://antoni.web.cern.ch/antoni/results/test30/geant4-09-06-ref-02/c_c_400/afig.gif

it is even more problematic for all models.
Comment 3 Alberto.Ribon 2014-07-02 20:22:55 CEST 
Gunter (to whom this bug is assigned to) said that this bug again is on Binary Light Ion cascade. This time Anton Ivantchenko reports on a un-physical peak in the energy distribution of secondary neutrons at small angles for low energy primaries. It is unclear if this is a problem or feature, and needs time even to reproduce.
Comment 4 Gunter.Folger 2015-02-03 09:54:19 CET 
The problem is reproduced. The cause is a bad handling of spectator neutrons when there is no spectator nucleus after the interaction. The spectator neutrons are added as secondaries with about the initial momentum, ignoring Fermi momentum. I need to find a way to transfer the Fermi momentum from initial to final state.