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Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5940&th=1753#msg_5940
I put here a couple of plots that demonstrate difference in deposited energy for Geant3, Geant4 VMC and native Geant4.
So cluster_energy_full.jpg -
is energy deposited from 1GeV photon in emc barrel (theta=50, phi=0-360).
And it is comparable with energy deposited in EmcTest setup (5x5 PbWO4 crystals), implemented by Stefano.
So around 5% of energy is lost somewhere for Geant4 and it doesn't come from complicated emc geometry.
So the difference doesn't come from the different Geant4 version
4.7 in Babar framework vs. 4.9 in pandaroot (which I also used in native Geant4 application).
So the source of difference is still under investigation,
Dima]]>Dima Melnychuk2008-02-22T11:20:53-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5942&th=1753#msg_5942
]]>StefanoSpataro2008-02-22T12:02:29-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5944&th=1753#msg_5944
And I used default cut value - 1mm, which is actually used in Babar framework.
In pandaroot in g4config.C there is a cut not in range but in energy - 1MeV, but when I run simulation in pandaroot whith Geant4 it prints energy cuts which correspond to 1 mm range cut for PWO (84.8 keV for gamma and 1.13 MeV for electrons) but if I put these values instead of 1 MeV the result is the same.
Dima]]>Dima Melnychuk2008-02-22T12:30:51-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5945&th=1753#msg_5945
Thanks for looking into this problem. I think we can learn a lot from it.
I had another question. I was wondering whether it would make sense to run the Geant4 mini-EMC detector within the Geant4-VMC templates provided by Ivana in cbmsoft/transport/geant4_vmc/examples/.... This would be a simulation with the "native" Geant4-VMC, which might differ from - lets say - the CBM/PandaRoot-VMC.
Kind wishes,
Johan. ]]>Johan Messchendorp2008-02-22T12:38:44-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5946&th=1753#msg_5946
In principle I planned it ("native" Geant4-VMC) as the next step.
Dima]]>Dima Melnychuk2008-02-22T12:42:09-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5947&th=1753#msg_5947
Let me know the outcome....
Johan.]]>Johan Messchendorp2008-02-22T12:45:19-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5964&th=1753#msg_5964
I tried to reproduce this problem, so I switched on only the emStandard list for G4 in the VMC which correspond to the PhysListEmStandard.cc used in native G4, i.e:
The result was as you can see in the attached figures some how acceptable!! So it seems that all the problem comes from the combination of the physics lists in VMC. So we need to investigate further what is going on here!
and drawing both over each other (G4 in red )
]]>Mohammad Al-Turany2008-02-25T20:26:25-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5966&th=1753#msg_5966
Just for completeness. Did you do a simulation with the 5x5 matrix? The reason why I am asking, is that I noticed that the response for G3 from Dima differ from the G3 from your simulation (albeit slightly, but nevertheless significant by looking at the average energy)....
Johan.]]>Johan Messchendorp2008-02-25T20:43:21-00:00Re: Geant 3, Geant 4 VMC, native geant 4 comparison
https://forum.gsi.de/index.phpindex.php?t=rview&goto=5967&th=1753#msg_5967
and here is the 5x5 matrix results: