[Gate-users] Ion source - timestamp problem GATE 6.1

[Enrique Muñoz Albaladejo]

Dear Gergely,

Thank you very much for the explanation. I have followed all your 
instructions and recompiled the code several times, but I couldn't get 
it to work properly. Even after changing the permission of isGeneralIon 
to public and explicitly setting it to be false the simulation time 
remains the same as before.

Did you manage to solve the issue like that?

I have tried to follow how the GATE code works, but it is too complex 
for my understanding. My uneducated (and probably wrong) guess is that 
the function GateVSource::GetNextTime( G4double timeStart ), where the 
lifetime of the ion is forced to 0, is not being called at all in my 
simulation.

Thanks again.

Best regards,

Enrique

On 13/01/16 09:42, Gergely Patay wrote:
> Dear Enrique,
>
> the ion timestamp problem is caused by a protected (i.e. non 
> user-settable) "isGeneralIon" field in the Geant4 G4ParticleDefinition 
> class (for the details, see 
> http://lists.opengatecollaboration.org/mailman/private/gate-users/2015-April/008344.html 
> ) .
>
> A minimal workaround might be as follows :
>
> 1) change visibility of isGeneralIon from protected to public:
> geant4/particles/management/include/G4ParticleDefinition.hh:402
> -   protected:
> +   public:
>        G4bool isGeneralIon;
>
> (this might be modified *without* recompiling Geant4)
>
> 2) add the following line to gate/source/physics/src/GateVSource.cc:269
>           GetParticleDefinition()->SetPDGLifeTime(0);
> +         GetParticleDefinition()->isGeneralIon=false;
>
> 3) recompile Gate with the modified header file.
>
> Since it requires to modify a file *outside* of the Gate source tree, 
> I'm not sure how to do it automatically.
>
> best regards,
>  Gergely
>
> -- 
> Gergely Patay
> Mediso Ltd.
>
>
> On 2016-01-12 18:09, Enrique Muñoz Albaladejo wrote:
>> Thank you very much for your response, the problem seems to be 
>> exactly as you
>> describe it. It looks like it ignores any time settings I define and 
>> takes the
>> time of the simulation to be that which makes the source run out of 
>> activity.
>>
>> I have encountered this problem when simulating a Na22 source with 
>> GATE 7.1 and
>> geant4.10.01.p02, and a colleague of mine has the same problem with 
>> GATE 6.1 and
>> Geant4 9.4 (she wanted to simulate 176 Lutetium).
>>
>> I tried to read through the Geant4 code and I can't figure out why 
>> the function
>> SetPDGLifeTime() would ignore the attempt to modify the lifetime of 
>> an ion, but
>> my programming knowledge isn't that deep.
>>
>> Thanks again.
>>
>> Enrique Muñoz
>>
>> On 04/01/16 09:37, STRYDHORST Jared wrote:
>>> What version of GATE and Geant4 are you using and what ion?
>>> GATE schedules the decay of ions itself according to the activity 
>>> set by the
>>> user. To do so, it calls a function that sets the lifetime of the 
>>> ion in
>>> Geant4 to zero so it decays immediately when it's created. However, 
>>> in version
>>> 10 (.1?, .2? I don't know exactly when the change was made.) of 
>>> Geant4, the
>>> function (SetPDGLifeTime()) now ignores any attempts to modify the 
>>> lifetime of
>>> an ion. So the ion is created by GATE, but then Geant4 calculates 
>>> the decay
>>> time according to the real half-life of the ion.
>>>
>>> Jared STRYDHORST
>>>
>>> Laboratoire Imagerie Moléculaire In Vivo (IMIV)
>>> UMR 1023 Inserm/CEA/Université Paris Sud - ERL 9218 CNRS
>>> CEA/I2BM/Service Hospitalier Frédéric Joliot
>>> 4, place du Général Leclerc
>>> 91401 ORSAY Cedex
>>>
>>> <mailto:karima.ait-aissa at cea.fr>
>>> <http://i2bm.cea.fr/dsv/i2bm/shfj/imiv>http://i2bm.cea.fr/dsv/i2bm/shfj/imiv 
>>>
>>> -------------------------------------------------------------------------------- 
>>>
>>> *De :* gate-users-bounces at lists.opengatecollaboration.org
>>> [gate-users-bounces at lists.opengatecollaboration.org] de la part de 
>>> Enrique
>>> Muñoz Albaladejo [Enrique.Munoz at ific.uv.es]
>>> *Envoyé :* lundi 21 décembre 2015 12:32
>>> *À :* gate-users at lists.opengatecollaboration.org
>>> *Objet :* [Gate-users] Ion source - timestamp problem GATE 6.1
>>>
>>> Dear all,
>>>
>>>
>>> I am trying to use an ion source for a PETscanner.
>>>
>>> The simulation provides strange values for the time stamp of the 
>>> singles.
>>> The parameter  "setTimeStop"  was set to 50s, but the timestamp of 
>>> the first
>>> detected single was 3.4x10^17 s.
>>>
>>> I would like to know if there is any solution to this problem.
>>>
>>> Best regards,
>>>
>>> Enrique
>>
>>
>>
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