I would like to simulate the creation of secondary electrons in various materials in the energy range down to 200 eV. I have read through the manuals and various posts on this forum which deals (atleast partially) with the subject, but I still dont manage to configure the simulations so that secondary electrons below 1 keV are generated (tracking below 1 kev is done correctly). Here are the relevant details of my simulation:
Geant4: 11.0.0
OS: Ubuntu 22.04
Settings in .mac file relevant for production and tracking:
/cuts/setLowEdge 300 eV
/run/setCut 10 fm (I have set it absurdly low to be sure that 1 kev electrons should pass)
/process/em/lowestElectronEnergy 10 eV
Physics-list: QGSP_BIC_HP_EMZ (also tried with _PEN, _LIV)
The output shows that a 1 keV cut is applied nonetheless:
Material : G4_AIR
Range cuts : gamma 10 fm e- 10 fm e+ 10 fm proton 10 fm
Energy thresholds : gamma 1 keV e- 1 keV e+ 1 keV proton 0.001 meV
and looking through the saved data, I dont see any secondary electrons produce below 1.02 keV
Anyone has an idea what I am missing? Any help is appreciated
Here a macro for example TestEm14, its printout, and the plot of histogram 3.
The key point is line ˜164 of PhysicsList.cc :
G4ProductionCutsTable::GetProductionCutsTable()-> SetEnergyRange(100eV, 1GeV)
which defines the range of the precomputed tables.
Thanks for the reply. I could reproduce the result using the example you suggested. I’m now building my own physicslist instead of using a reference one, and I set the energy cuts in the setcut function as you indicated. Looking at the output, the values takes effect
Electromagnetic Physics Parameters Min kinetic energy for tables 109 eV Max kinetic energy for tables 1 GeV
but the energy thresholds are still at 1 keV
Index : 0 used in the geometry : Yes Material : G4_AIR Range cuts : gamma 10 nm e- 10 nm e+ 10 nm proton 10 nm Energy thresholds : gamma 1 keV e- 1 keV e+ 1 keV proton 1 eV
so there is an additional problem somewhere. I continue to work on it.
