Problem 132

Summary: Polarized Compton Scattering azimuthal dependencies
Product: Geant4 Reporter: ruisilva
Component: processes/electromagneticAssignee: Michel.Maire
Status: CLOSED FIXED    
Severity: normal    
Priority: P2    
Version: 1.1   
Hardware: PC   
OS: Linux   

Description ruisilva 2000-07-16 19:20:04 CEST
G4PolarizedComptonScattering.cc has a function, SystemOfRefChange, that
should be responsable for the new direction of the photon. It is suposed
that its new direction follow the polarization dependent Klein-Nishima
distribution, independently of the polarization vector orientation.

The function SystemOfRefChange doesn't follow the same criteria for
perpendicular polarization vectors. For example:

- Direction of propagation: X=1, Y=0 and Z=0 and Polarization vector:
X=0, Y=1 and Z=0, results in a oposite final direction (Direction1 in
function) of that of a polarization vector: X=0, Y=-1 and Z=0.
 For the same direction of propagation and polarization vectors:
X=0, Y=0, Z=1 and Z=-1, the final direction is no longer oposite,
but the same.

The final direction depends not only of the polarization Klein-Nishima
distribution, but also of the orientation of polarization vector to
the reference system.

Was the polarization Klein-Nishima distribution verified by testing
this file?

Another problem arose when I pick novice N03 example and changed the
normal Compton Scattering for the Polarized Compton Scattering.
When I sent a beam of polarized photons the program aborted and gave
the following message:

Invalid enum in G4Box::CalcNormal

***G4Exception: Aborting execution ***
Abort (core dumped)

Could this be due to the problem already reported about in "geomtry/
volumes" caused by volume replica?