I have encountered a problem when trying to use the G4EmLivermorePhysics list with Geant4 standard exampleB1
(that I only slightly modified with another geometry for my purpose of simulating gamma-ray interactions in a Ge-crystal).
The output (with geant4.10.05-p01) shows a minimum threshold energy of 200 keV for the photoelectric effect as shown below.
This far exceeds the default of 250 eV specified in documentation:
phot: for gamma SubType=12 BuildTable=0
LambdaPrime table from 200 keV to 100 TeV in 61 bins
===== EM models for the G4Region DefaultRegionForTheWorld ======
LivermorePhElectric : Emin= 0 eV Emax= 100 TeV SauterGavrila Fluo
The process of my incorportation of the G4EmLivermorePhysics list was done in 3 major steps.
- In the default physics list geant4.10.05/geant4.10.05.p01/source/physics_lists/lists/src/QBBC.cc
the following lines were commented out
// RegisterPhysics( new G4EmStandardPhysics(ver) );
The following lines were added
RegisterPhysics( new G4EmLivermorePhysics(ver) );
This did not affect the 200 keV lower threshold.
- Removed added lines from step 1 and added the lines
RegisterPhysics( new G4EmLowEPPhysics(ver) );
This did not affect the 200 keV lower threshold either.
- The final option was to try to manually set the energy range in the CutsTable
in the file geant4.10.05/geant4.10.05.p01/source/run/src/G4VUserPhysicsList.cc
with the possibility that this change in dynamic range might result in a better computed lower energy boundary for the table dumped above.
However, this did not affect the 200 keV lower threshold either.
Does anyone know an effective way to force the lower energy threshold for the initialized photoelectric table applying the Livermore model
down to 1 keV instead of default 200 keV?
Your assistance in this matter would be much appreciated.