[Gate-users] 22-Na positron source.

[Patay Gergely]

Dear Andrea,

I just used Gate7 for the same purpose a few weeks (and Gate5 a few years) ago, 
and worked like a charm.
A very useful debugging tool is the verbose output of geant4, invoked by
/tracking/verbose 1
(be prepared for a *huge* amount of data on stdout).
If you see lines like

* G4Track Information:   Particle = Na22[0.0],   Track ID = 1,   Parent ID = 0
(...)
* G4Track Information:   Particle = nu_e,   Track ID = 3,   Parent ID = 1
(...)
* G4Track Information:   Particle = Ne22[1274.6],   Track ID = 2,   Parent ID = 1
(...)
* G4Track Information:   Particle = e+,   Track ID = 4,   Parent ID = 1
Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng 
NextVolume ProcName
(...)
    3    0.939    0.117    0.428         0        0        0      1.34 
world_phys annihil

then everything is working perfectly.

Actually, you can only access the history of the migrating positrons from this 
output, the usual root or ascii output will know only about particles reaching 
the detectors, so an empty *Hits.dat file is not necessarily a sign of error.

cheers
  Gergely



On 2015-03-23 10:15, Andrea González wrote:
>
> Hi again, sorry for my insistence. I need a 22-Na source emitting positron
> because I want to study positrons annihilation range.
> How can I do that?
>
> A kindly collaborator proposses me this:
>
> /gate/source/addSource na22
> /gate/source/na22/setActivity 10000 Bq
> /gate/source/na22/gps/particle ion
> /gate/source/na22/gps/ion 11 22 0 0
> /gate/source/na22/gps/monoenergy 0. keV
> /gate/source/na22/gps/type Plane
> /gate/source/na22/gps/shape Circle
> /gate/source/na22/gps/radius 0.5 mm
> /gate/source/na22/gps/angtype iso
> /gate/source/na22/gps/centre 0. 0. 0. cm
>
> In your physics list you have to enable radioactive decay:
> /gate/physics/addProcess Decay
> /gate/physics/addProcess RadioactiveDecay GenericIon
>
>
> But it isn´t emitting positrons...
>
>
> Thank you all.
>
>
>
>
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