G4WaterStopping in EM_std_option3/4 during 10.00, and >=10.00.p1

Physics Processes, Models and Cross Sections
1

Dear expert,

I am using G4EmStandardPhysics_option3/4 to simulate carbon interacting with water.
Here is the ionization of GenericIon in option3.
https://geant4.kek.jp/lxr/source/physics_lists/constructors/electromagnetic/src/G4EmStandardPhysics_option3.cc?v=10.0.p1#L272

For GenericIon, I found ‘G4WaterStopping’ was active in 10.00 version,
however, from 10.00.p1, it was inactive.

https://geant4.kek.jp/lxr/source/processes/electromagnetic/standard/src/G4ionIonisation.cc?v=10.0#L158

https://geant4.kek.jp/lxr/source/processes/electromagnetic/standard/src/G4ionIonisation.cc?v=10.0.p1#L151

As my investigation, the ‘G4WaterStopping’ seems to affect the effective charge and dedx in low energy.
I would like what the ‘G4WaterStopping’ is, why we do not need to think about it from 10.00.p1.

Thanks in advance!
Best,
Ye

2

Hello,

in Opt3/Opt4 we are using ICRU73 stopping power data and not G4WaterStopping class.

VI