Geant4 Version: geant4-10-07-patch-04 (9-September-2022)
Operating System: Linux Centos 8
Compiler/Version: g++ (GCC) 8.5.0 20210514 (Red Hat 8.5.0-18)
CMake Version: 3.20.2
Hello everyone,
I am conducting an experiment to determine the positron range for various chemical elements. The setup is as follows: A cubic world volume with (9.5* m^3) filled with G4_K (Potassium), Physics list: emstandardSS, and setEnergy: 511.0 keV. The experiment starts with shooting positrons.
When an electron (as a secondary element) is produced in an event, it do not change its position and all most do not lose its energy. Hence, in my stepping action I kill the electrons (as well as the gamma rays since I am looking for positron range).
However, after killing the electrons, after a few events, even positrons never lose their energies even after more than 1 million steps (see below).
Interestingly, for Single Scattering (SS), this phenomenon (where positrons and electrons do not lose their energies) doesn’t occur when I replace the world volume’s element from G4_K to G4_Si, G4_Ti, or G4_S. Furthermore, when I switch from SS to MSC (like ‘emstandard_opt3’ or ‘emstandard_opt4’), this issue disappears even when the volume is filled with G4_K (even without killing the electron).
Can someone help me understand why G4_K combined with SS behaves this way? Is this an inherent issue with Geant4, or might I be overlooking something in my setup?
Electrons are present:
*********************************************************************************************************
* G4Track Information: Particle = e+, Track ID = 1, Parent ID = 0
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 0 0 0 0.452 0 0 0 pvWorld initStep
1 8.72e-06 8.4e-06 -4.45e-06 0.452 1.77e-06 1.29e-05 1.29e-05 pvWorld CoulombScat
2 9.58e-05 9.32e-05 -4.9e-05 0.452 0 0.000129 0.000142 pvWorld CoulombScat
3 0.000293 0.000278 -0.00015 0.452 0 0.000289 0.000431 pvWorld CoulombScat
4 0.00057 0.000534 -0.000289 0.452 2.06e-05 0.000402 0.000833 pvWorld CoulombScat
5 0.000791 0.000741 -0.0004 0.452 1.02e-05 0.000322 0.00116 pvWorld CoulombScat
.
.
.
36092 -0.26 0.362 0.629 0.167 0 8.08e-05 1.68 pvWorld CoulombScat
36093 -0.26 0.362 0.629 0.167 0 0.000503 1.69 pvWorld CoulombScat
36094 -0.259 0.362 0.629 0.167 0.000157 0.000159 1.69 pvWorld CoulombScat
36095 0.00968 0.689 0.87 0 0.167 0.487 2.17 pvWorld eIoni
36096 0.00968 0.689 0.87 0 0 0 2.17 pvWorld annihil
*********************************************************************************************************
* G4Track Information: Particle = gamma, Track ID = 3, Parent ID = 1
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 0.00968 0.689 0.87 0.511 0 0 0 pvWorld initStep
1 -6.54 3.73 1.23 0.461 1.87e-05 7.23 7.23 pvWorld compt
*********************************************************************************************************
* G4Track Information: Particle = e-, Track ID = 4, Parent ID = 3
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 -6.54 3.73 1.23 0.0503 0 0 0 pvWorld initStep
1 -6.54 3.73 1.23 0.0503 3.46e-17 8.11e-17 8.11e-17 pvWorld CoulombScat
2 -6.54 3.73 1.23 0.0503 1.13e-16 2.66e-16 3.47e-16 pvWorld CoulombScat
3 -6.54 3.73 1.23 0.0503 2.83e-17 6.65e-17 4.13e-16 pvWorld CoulombScat
4 -6.54 3.73 1.23 0.0503 9.25e-18 2.17e-17 4.35e-16 pvWorld CoulombScat
5 -6.54 3.73 1.23 0.0503 7.02e-17 1.65e-16 6e-16 pvWorld CoulombScat
.
.
.
1391590 -6.54 3.73 1.23 0.0503 6.49e-17 1.52e-16 4.5e-10 pvWorld CoulombScat
1391591 -6.54 3.73 1.23 0.0503 1.96e-16 4.6e-16 4.5e-10 pvWorld CoulombScat
1391592 -6.54 3.73 1.23 0.0503 5.63e-17 1.32e-16 4.5e-10 pvWorld CoulombScat
1391593 -6.54 3.73 1.23 0.0503 1.29e-16 3.02e-16 4.5e-10 pvWorld CoulombScat
1391594 -6.54 3.73 1.23 0.0503 2.19e-16 5.13e-16 4.5e-10 pvWorld CoulombScat
1391595 -6.54 3.73 1.23 0.0503 1.18e-16 2.76e-16 4.5e-10 pvWorld CoulombScat
After killing the electron:
34957 -0.359 0.745 -0.375 0.167 6.15e-07 2.96e-06 1.42 pvWorld CoulombScat
34958 -0.359 0.745 -0.375 0.167 9.58e-06 4.6e-05 1.42 pvWorld CoulombScat
34959 -0.359 0.745 -0.375 0.167 5.97e-06 2.87e-05 1.42 pvWorld CoulombScat
34960 -0.359 0.746 -0.375 0.167 0 0.000166 1.42 pvWorld CoulombScat
34961 -0.358 0.746 -0.375 0.167 0 5.79e-05 1.42 pvWorld CoulombScat
34962 -0.358 0.746 -0.375 0.167 0.000104 7.59e-05 1.42 pvWorld CoulombScat
34963 -0.0177 1.02 -0.585 0 0.167 0.488 1.91 pvWorld eIoni
34964 -0.0177 1.02 -0.585 0 0 0 1.91 pvWorld annihil
*********************************************************************************************************
* G4Track Information: Particle = gamma, Track ID = 3, Parent ID = 1
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 -0.0177 1.02 -0.585 0.511 0 0 0 pvWorld initStep
1 -6.21 -4.07 -9.7 0.24 1.87e-05 12.1 12.1 pvWorld compt
*********************************************************************************************************
* G4Track Information: Particle = e-, Track ID = 4, Parent ID = 3
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 -6.21 -4.07 -9.7 0.271 0 0 0 pvWorld initStep
1 -6.21 -4.07 -9.7 0.271 3.94e-06 2.41e-05 2.41e-05 pvWorld CoulombScat
*********************************************************************************************************
* G4Track Information: Particle = gamma, Track ID = 2, Parent ID = 1
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 -0.0177 1.02 -0.585 0.511 0 0 0 pvWorld initStep
1 119 99.1 175 0.219 1.9e-05 234 234 pvWorld compt
*********************************************************************************************************
* G4Track Information: Particle = e-, Track ID = 5, Parent ID = 2
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 119 99.1 175 0.292 0 0 0 pvWorld initStep
1 119 99.1 175 0.292 5.85e-06 3.68e-05 3.68e-05 pvWorld CoulombScat
*********************************************************************************************************
* G4Track Information: Particle = e+, Track ID = 1, Parent ID = 0
*********************************************************************************************************
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName
0 0 0 0 0.295 0 0 0 pvWorld initStep
1 4.61e-05 -2.77e-05 -2.55e-05 0.295 9.46e-06 5.95e-05 5.95e-05 pvWorld CoulombScat
2 0.000267 -0.000161 -0.000147 0.295 1.15e-05 0.000285 0.000345 pvWorld CoulombScat
3 0.000428 -0.000256 -0.000234 0.295 0 0.000207 0.000551 pvWorld CoulombScat
4 0.000605 -0.000364 -0.000332 0.295 0 0.000229 0.000781 pvWorld CoulombScat
5 0.000654 -0.000393 -0.00036 0.295 0 6.37e-05 0.000844 pvWorld CoulombScat
6 0.00105 -0.000625 -0.00057 0.294 0.000394 0.000503 0.00135 pvWorld CoulombScat
7 0.00144 -0.000854 -0.000778 0.293 0.00121 0.000498 0.00185 pvWorld CoulombScat
8 0.00145 -0.000857 -0.000782 0.293 1.25e-06 7.87e-06 0.00185 pvWorld CoulombScat
9 0.0017 -0.00101 -0.000921 0.293 0 0.000328 0.00218 pvWorld CoulombScat
10 0.00203 -0.0012 -0.00108 0.293 0 0.000416 0.0026 pvWorld CoulombScat
11 0.00247 -0.00147 -0.0013 0.293 0.000136 0.000562 0.00316 pvWorld CoulombScat
12 0.00247 -0.00147 -0.0013 0.293 2.96e-08 1.86e-07 0.00316 pvWorld CoulombScat
13 0.00274 -0.00163 -0.00144 0.293 0 0.000338 0.0035 pvWorld CoulombScat
14 0.00274 -0.00164 -0.00144 0.293 1.5e-06 9.39e-06 0.00351 pvWorld CoulombScat
15 0.0028 -0.00167 -0.00147 0.293 0 6.52e-05 0.00357 pvWorld CoulombScat
.
.
.
1079858 5.84e-06 4.14e-05 -7.73e-06 0.109 3.32e-11 1.24e-10 9.04e-05 pvWorld CoulombScat
1079859 5.84e-06 4.14e-05 -7.73e-06 0.109 1.97e-11 7.37e-11 9.04e-05 pvWorld CoulombScat
1079860 5.84e-06 4.14e-05 -7.73e-06 0.109 4.08e-11 1.53e-10 9.04e-05 pvWorld CoulombScat
1079861 5.84e-06 4.14e-05 -7.73e-06 0.109 4.17e-11 1.56e-10 9.04e-05 pvWorld CoulombScat
1079862 5.84e-06 4.14e-05 -7.73e-06 0.109 2.21e-12 8.27e-12 9.04e-05 pvWorld CoulombScat
1079863 5.84e-06 4.14e-05 -7.73e-06 0.109 2.15e-11 8.03e-11 9.04e-05 pvWorld CoulombScat
1079864 5.84e-06 4.14e-05 -7.73e-06 0.109 1.15e-11 4.3e-11 9.04e-05 pvWorld CoulombScat
1079865 5.84e-06 4.14e-05 -7.73e-06 0.109 7.25e-11 2.71e-10 9.04e-05 pvWorld CoulombScat