The microelectronics example illustrates the possibility to combine discrete and condensed history processes in Geant4 at different geometrical scales and in selected regions in a unique Geant4 application, thanks to the common software design adopted by the electromagnetic physics Working Group of the Geant4 collaboration.
It simulates the track of a 5 MeV proton in silicon. Geant4 standard EM models are used in the World volume while G4MicroElecPhysics (for Ag, Al, C, Cu, Ge, Kapton, Ni, SiO2, Ti or W materials) or G4MicroElecPhysicsSi (dedicated to Si) models are used in a Target volume, declared as a Geant4 Region.
Simulated experimental setup
The geometry is a 1 um side cube (World) made of silicon containing a smaller cubic Target volume of silicon (G4_Si). The cube material can be replaced by G4_Ag, G4_Al, G4_C, G4_Cu, G4_Ge, G4_KAPTON, G4_Ni, G4_SILICON_DIOXIDE, G4_Ti or G4_W into the input file.
This example shows:
- how to use the G4MicroElecPhysics or G4MicroElecPhysicsSi processes,
- how to combine them with Standard electromagnetic physics.
A simple electron capture process is also provided in order to kill electrons below a chosen energy threshold, set in the Physics List. Look at the MicroElecSiPhysics.cc and MicroElecPhysics.cc files.
The output results consist in a
microelectronics.root file (http://root.cern.ch), containing in an ntuple for each simulation step:
- the type of particle for the current step
- the type of process for the current step
- the current preStepPoint (in nanometers)
- the energy deposit along step
- the step length
This file can be easily analyzed using for example the provided ROOT macro file plot.C.
The naming scheme of particles and processes used is described in SteppingAction.cc.
Last updated: 05/02/2022 by S. Guatelli