Problem 1529

I can confirm this problem for a different element. Seems to be a problem of the G4RadioactiveDecay process.

I am simulating the radioactive decay of Lu176, which decays via beta- emission to Hf176. The physics list for this is G4RadioactiveDecayPhysics().
When the emitted gammas hit an electron of a different atom, the binding energy of the electron is the deposited energy of the gamma. The remaining energy is deposited by the electron.

Now to the problem:
When the gamma interacts with an electron of the decayed core, the gamma is not tracked / included in the output. Only the resulting electron is reported. 
The problem is, that the energy of the hole is not included in the total deposited energy of the event.

Output example:
Event ID, Dep En, Start En, Part ID, Process 
Normal case:

4180 545.962 545.962 11 RadioactiveDecay Decay
4180 0.00237764 0.00237764 1000721761 RadioactiveDecay Decay
4180 77.6807 77.6807 11 RadioactiveDecay Decay
4180 63.314 201.83 22 RadioactiveDecay Decay
4180 63.314 306.78 22 RadioactiveDecay Decay
4180 107.674 107.674 11 phot Electromagnetic
4180 135.792 135.792 11 compt Electromagnetic
4180 138.516 138.516 11 phot Electromagnetic

Here the two gammas (ID 22) deposit the binding energy and the according electrons (183.51+63.314=201.83 etc) deposit the remaining energy of the gamma. 

Problem case:

4182 196.132 196.132 11 RadioactiveDecay Decay
4182 0.00152082 1000721761 RadioactiveDecay Decay
4182 136.479 136.479 11 RadioactiveDecay Decay
4182 23.0689 23.0689 11 RadioactiveDecay Decay


In this case a 201.83 keV gamma and a 88.35 keV gamma interact with an K shell electron with a binding energy of 65.35 keV of the Hf176 core. The hole energy is then missing.

Hi Susana and Robert,

   A lot of things were fixed in the radioactive decay model between Geant4 V9.6 and V10.0, so I suggest switching to 10.0. In particular, the missing energy you mentioned is now there, which you can verify by running extended example rdecay01 (examples/extended/radioactivedecay/rdecay01).
   I developed a short macro for this:
#
/gun/particle ion
/rdecay01/event/printModulo 1
/rdecay01/fullChain true
/control/verbose 1
#
/gun/ion 82 210 82 0
/run/beamOn 10
#
/gun/ion 71 176 71 0
/run/beamOn 10

   Running this for 10 events in 210Pb and 176Lu shows all the expected levels:

end of event 0 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206 
end of event 2 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 3 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 4 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 1 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 5 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 6 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 8 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 7 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206
end of event 9 : Pb210 ---> Bi210[46.539] ---> Bi210 ---> Po210 ---> Pb206

 Nb of generated particles: 

        Bi210:      10  Emean = 0.005224 eV   ( 0.000291 eV  --> 0.02122 eV )
Bi210[46.539]:      10  Emean = 0.005224 eV   ( 0.000291 eV  --> 0.02122 eV )
        Pb206:      10  Emean =  103.9 keV    ( 102.7 keV --> 104.9 keV)
        Po210:      10  Emean =  1.905 eV     ( 0.09558 eV  --> 3.86 eV )
        alpha:      10  Emean =  5.339 MeV    ( 5.338 MeV --> 5.341 MeV)
    anti_nu_e:      20  Emean =  419.5 keV    ( 7.53 keV --> 1.138 MeV)
           e-:      28  Emean =    131 keV    ( 90.6 eV  --> 752.5 keV)
        gamma:       2  Emean =  46.54 keV    ( 46.54 keV --> 46.54 keV)

Note: for Pb, most of the gammas at 46.54 keV actually come out as internal conversion e-

==========================================================================================

end of event 0 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176 
end of event 1 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176 
end of event 4 : Lu176 ---> Hf176[997.730] ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 5 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 6 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 7 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 8 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 9 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 2 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176
end of event 3 : Lu176 ---> Hf176[596.820] ---> Hf176[290.039] ---> Hf176[88.209] ---> Hf176


 Nb of generated particles: 

         Hf176:      10  Emean = 0.4506 eV     ( 0.001077 eV  --> 1.227 eV )
Hf176[290.039]:      10  Emean = 0.4506 eV    ( 0.001077 eV  --> 1.227 eV )
Hf176[596.820]:      10  Emean = 0.4506 eV    ( 0.001077 eV  --> 1.227 eV )
 Hf176[88.209]:      10  Emean = 0.4506 eV     ( 0.001077 eV  --> 1.227 eV )
Hf176[997.730]:       1  Emean = 0.001077 eV  ( 0.001077 eV  --> 0.001077 eV )
     anti_nu_e:      10  Emean =  433.1 keV    ( 161.5 keV --> 591.5 keV)
            e-:      19  Emean =  100.5 keV    ( 1.83 keV --> 333.6 keV)
         gamma:      22  Emean =  243.1 keV    ( 88.21 keV --> 401 keV)

Created attachment 276 [details]
illustration of lu176 decay

Well I am sorry but the Bug I mentioned is not fixed (Geant4 10.0.1).
I will try to explain the issue again:

I am simulating the radioactive decay of Lu176 atoms in an LSO crystal. The complete crystal volume is set as a source volume for the decaying atoms.
Now there are three possible options for the gammas when an Lu176 atom decays:
1. The emitted gammas leave the crystal (no interaction - not interesting)
2. Interaction with electrons of another atom (mostly other Lu176 atoms)
3. Interaction with electrons of its own core (Lu176 -> Hf176)

I prepared a sketch for a better illustration of option 2 and 3 where an Lu176 atom decays and creates an excited Hf176 atom.
Option 2:
When a gamma (e.g. 201.83 keV) interacts with the electron (1s - 63.3 keV binding) of another atom the following happens:
The gamma deposits the binding energy of the electron. An electron with the kinetic energy of E = E_gamma - E_binding is created.
This is is simple physics and absolutely correct. The cyan colored bubbles in the sketch represent the deposited energies / particles which Geant4 takes into account. The binding energy is colored red and is deposited by the gamma (See previous post of mine).

Option 3:
When a gamma interacts with the electron of the core it was emitted from the following happens:
An electron with the kinetic energy of E = E_gamma - E_binding is created. But here the energy of the created hole (binding energy) is missing an the energy budget is simply wrong. 

I think the problem here is that the information for the decay is simply taken from for example nudat. And of course e.g. K-shell electrons are ejected just according to nudat. But these electrons do not simply appear but are ejected because of interior interaction of electrons and gammas near the decaying core. The ejected electron leaves a hole with an energy of up to 65.35 keV. This hole is then filled with another electron which ejects an other gamma or the energy is simply dissipated thermally. But still the energy of the hole has to appear just like in option 2.


If i would only use the Lu176 as an external source using the nudat data might be correct, but since the source is internal the energy of the hole has to be dissipated in the crystal.


I hope i could make my point clear. If you have any questions please contact me. 


Note:
In my previous post is a transposed digit: It has to be "Here the two gammas (ID 22) deposit the binding energy and the according
electrons (138.51+63.314=201.83 etc) deposit the remaining energy of the gamma. "