FLUKA: fluka-geant comparison

[Aaron Yarritu <ayarritu@SLAC.Stanford.EDU>]

Dear Sirs,

Hello, I am a graduate student working on a simulation of a muon passing
through a quartz bar.  In particular, I am interested in the delta rays
that are generated by the muon.  Using FLUKA, I have simulated the setup
and have recorded the properties of delta rays that the muon knocked off.
I have also done this with GEANT4 with the exact setup.  In the file
attached, there are two graphs (one that used GEANT and the other
which used FLUKA) which have 4700 delta rays each.  In each
graph, the energy (in MeV) of the delta ray is plotted versus the angle of
emission (in degrees) with respect to the track.  Using relativistic
kinematics, one can also theoretically determine the dependence of energy
versus angle.  This curve is shown in the dotted line for both graphs.  It
seems the FLUKA seems to have more of a distribution about this curve than
does GEANT.  So, my question is, why is this is?  Does FLUKA use a different
algorithm than GEANT?

any help is appreciated.  if you have any questions, please feel free to
contact me.

Sincerely,
Kevin

energyvsangle.ps