Problem 619

Summary:	G4BinaryLightIonReaction.cc problem w. heavy projectiles on light targets?
Product:	Geant4	Reporter:	corneliu
Component:	processes/hadronic/models	Assignee:	Hans-Peter.Wellisch
Status:	RESOLVED FIXED
Severity:	normal
Priority:	P2
Version:	6.1
Hardware:	PC
OS:	Linux

Description corneliu 2004-04-28 03:48:05 CEST

Hi,
 I was recently trying to interpret some very strange results obtain using the
G4BinaryLightIonReaction model. I was simulating the passage of C, N, O beams
(~700MeV/amu) through a thin carbonaceous material (plastic scintillator). For
the Carbon beam the results (ie. number transmitted primary ions) were sensible
whereas those for N and O beams were much lower than expected. Whilst simulating
with visualisation most, if not all, products originating from N,C or O,C
reactions were emitted in the direction contrary to that of the primary beam. I
tried this out with a number of projectile/target combinations and observed
similar results. In G4BinaryLightIonReaction::ApplyYourself the target and
projectile are swapped if the projectile is heavier than the target. Perhaps
there is a problem with this swapping procedure (or in the re-transformation of
products after the reaction)??
Best Regards,
Iwan

Comment 1 Hans-Peter.Wellisch 2004-05-25 07:41:59 CEST

a known problem. I inverse kinematics target lighter than projectile). We are
working to fix it.

Many greetings,

Hans-Peter.

Comment 2 Hans-Peter.Wellisch 2004-06-07 09:19:59 CEST

Finally managed to identify this. It was a wrong orientation of the Breit frame
in iverse kinematics. Will be fixed in 6.2.

Many greetings,

Hans-Peter.