Dear Geant4 Experts,
I am conducting research on ion-induced primary knock-on atom (PKA) production in reactor structural materials, with the broader goal of establishing a computational framework for selecting ion irradiation conditions that reproduce neutron-induced primary radiation damage.
I have already performed related calculations using FLUKA. However, FLUKA cannot directly extract the individual target recoil energies generated by charged-particle screened Coulomb nuclear scattering.
To address this limitation, I am investigating Geant4’s G4ScreenedNuclearRecoil model, particularly the implementation available in the TestEm7 example.
My initial simulation setup as an example is:
- Incident particle: Proton (10 MeV, monoenergetic)
- Target: Pure Fe
- Geometry: Fe slab with normal beam incidence
- Interaction: Screened nuclear elastic scattering
- Recoils of interest: First-generation Fe PKAs produced directly by primary protons
I aim to calculate the PKA energy spectrum (dN/dE), depth distribution (dN/dz), and two-dimensional energy–depth distribution (d²N/dE dz), normalized per incident proton.
I would greatly appreciate guidance on the following questions:
- Is
G4ScreenedNuclearRecoilappropriate for explicitly generating Fe recoils from 10 MeV proton-induced screened Coulomb scattering? - What is the recommended method for extracting the kinetic energy, production depth, parent particle, and creator process of each first-generation Fe recoil?
- How should the recoil-production threshold and physics configuration be defined to avoid missing low-energy recoils or double-counting elastic scattering?
- Can these recoil spectra be considered physically reliable after appropriate validation, and what independent benchmarks would you recommend?
I would be happy to share my Geant4 source files and simulation results for review.
Geant4 Version: 11.4.3
Operating System: Ubuntu 26.04.1 LTS
Compiler/Version: GCC/G++ 15.2.0
CMake Version: 4.2.3