Direction of delta electrons

Physics Processes, Models and Cross Sections
1

Please fill out the following information to help in answering your question, and also see tips for posting code snippets. If you don’t provide this information it will take more time to help with your problem!

Geant4 Version: 11.2.2
Operating System: MacOS 14.5
Compiler/Version: clang-1500.3.9.4
_CMake/
WC_angle_energy
Version:_3.30.1

Hi,

I’m simulation delta-electron production from a thin wire. Here I use 3 GeV proton beam and the target is a wire with diameter of 33 um, made of Carbon or Tungsten. Physics list is G4EmStandardPhysics_option4. I save particle parameters using this condition:

if(aTrack->GetVolume()->GetName()==“Wire” && aTrack->GetNextVolume()->GetName()==“World” && aTrack->GetDynamicParticle()->GetPDGcode()==11)

and use GetMomentumDirection() to find at which angle the electrons are moving.
The attached plot shows the energy of registered electrons in function of emission angle. 0 degree is straight along the proton beam. The crocodile-like shape, especially visible for Carbon target, is puzzling me. What physics process gives such dependency? Or is this an artefact of the simulation?

Best regards, Mariusz

1 Like
2

@sapinski
Pretty interesting. I suggest you to look mat properties first.
My further suggestion can be to change wire from carbon to say Aluminum (true metal).

And compare two true metals graphs i.e. Al and W

V

3

hello,

some part of the plot are electrons with zero energy. Where they come from? Normally electrons should be produced above the production threshold, are they from primary particles or from secondary?

VI