Energy loss of secondaries from radioactive decay

Particles, Track, Event, Run and Biasing
1

Hi,

I am trying to simulate a radioactive source irradiating a material. I’m fairly new but I’ve managed to run my code based on the B1 and rdecay01 examples. I’ve also included a sensitive detector class, as I am interested in the energy deposit in my target material. In DetectorConstruction.cc, I’ve specified the characteristics of the detector (geometry, shape, location,etc.). When I run it see that all of the secondaries from the radioactive particle do not deposit any energy in the medium.

For example. An electron shows:

  • G4Track Information: Particle = anti_nu_e, Track ID = 6, Parent ID = 2

Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process
0 -1.55 cm -3.22 mm 4.69 cm 1.07 MeV 0 eV 0 fm 0 fm container initStep
1 -1.52 cm -3.11 mm 4.49 cm 1.07 MeV 0 eV 1.97 mm 1.97 mm container Transportation
2 -7.93 mm -726 um 4.9 mm 1.07 MeV 0 eV 4.07 cm 4.27 cm Envelope Transportation
3 -7.69 mm -646 um 3.55 mm 1.07 MeV 0 eV 1.37 mm 4.41 cm chip package Transportation
4 -7.65 mm -634 um 3.35 mm 1.07 MeV 0 eV 204 um 4.43 cm chip silicion Transportation
5 -7.4 mm -554 um 2 mm 1.07 MeV 0 eV 1.37 mm 4.57 cm chip package Transportation
6 -6.68 mm -316 um -2 mm 1.07 MeV 0 eV 4.07 mm 4.97 cm PCB Transportation
7 8.37 cm 2.93 cm -50 cm 1.07 MeV 0 eV 50.7 cm 55.7 cm Envelope Transportation
8 10.2 cm 3.52 cm -60 cm 1.07 MeV 0 eV 10.2 cm 65.9 cm World OutOfWorld

As you can see, “dEStep” is always 0eV. This applies for secondaries I see. Do you have any suggestions why this is the case?

Cheers,
johan

2

What you showed us is not an electron, it’s a neutrino. Neutrinos don’t lose energy, they just keep going :slight_smile:

3

Hi,

Sorry. I copied the wrong snipped of the output. Here is the one from the electron

> *********************************************************************************************************
> * G4Track Information:   Particle = e-,   Track ID = 7,   Parent ID = 2
> *********************************************************************************************************
> Step#      X         Y         Z        KineE    dEStep   StepLeng  TrakLeng    Volume     Process
> 0  -2.31 cm   -6.9 mm   4.88 cm   1.69 MeV     0 eV      0 fm      0 fm     source   initStep
> 1  -1.06 cm  -1.13 cm   4.69 cm   1.69 MeV     0 eV   1.34 cm   1.34 cm     source   Transportation
> 2   1.77 cm  -2.13 cm   4.25 cm   1.69 MeV     0 eV   3.03 cm   4.37 cm  container   Transportation
> 3     50 cm  -19.2 cm  -3.21 cm   1.69 MeV     0 eV   51.7 cm   56.1 cm   Envelope   Transportation
> 4     60 cm  -22.8 cm  -4.75 cm   1.69 MeV     0 eV   10.7 cm   66.8 cm      World   OutOfWorld
4

Hi,

I managed to resolve it. It turns out that the PhysicsList.cc was incomplete. It only accounted for transport.

Cheers,
j

5

Hi, does your particle travel after decay or they stop after travelling some distance?