[Gate-users] Ion source - timestamp problem Gate 6.0.1

[Uwe Pietrzyk]

Hi Didier,

I tried this issue with GATE 6.1 and found the same problem as Mercedes in
her runs. Using ion sources (ex: O-15) give simply crazy time stamps, starting with:

1.01108082430250235006497e+02  !!

according to the ascii printout of "singles".

Using a simple positron source with O-15 decay times I receive:

9.08127148493307485720334e-07 !!,

which to me look quite different. Something is wrong there.
As I mentioned some time ago, also the scatter fractions look
differently.  

Kind regards,

Uwe
-----
On 30.03.2011, at 04:48, Didier Benoit wrote:

> Hi Mercedes,
> 
> Could you test your macro with GATE 6.1? Many bugs have been fixed concerning the sources in GATE.
> 
> Kind Regards,
> Didier Benoit
> 
> On Mar 22, 2011, at 7:16 PM, Mercedes Rodriguez wrote:
> 
>> Dear Gate Users,
>> 
>> I'm trying to use an ion source (18F, 22Na or 15O) for a PETscanner geometry and the simulation provides strange results for the timestamps. For instance, I run the simulation using 18F, setTimeSlice=60 s and the time histogram for coincidence events goes from 0 to ~100000 s, following an exponential decay. No randoms and no scattered events are produced. My guess is that time sampling is incorrect when using an ion source.
>> 
>> When I run the simulation for e+ that have an 18F energy spectrum (and the corresponding half life) I obtain randoms and scattered events different from zero and the time histogram is what I expect, flat from 0 to 60 s. I'm attaching a pdf file with a couple of graphs for 18F (ion source and e+), Ao=4e5 Bq, TimeSlice=60s.
>> 
>> Any idea of what could be happening?
>> 
>> Regards.
>> Mercedes
>> 
>> -- 
>> Mercedes Rodriguez Villafuerte, Ph.D.
>> Visiting Professor, Cherry's Lab
>> BME, UC Davis
>> 451 Health Sciences Drive, GBSF 2505
>> Davis, CA 95616
>> 
>> Tel: 530-752-6387
>> 
>> <IonSource.pdf>_______________________________________________
>> Gate-users mailing list
>> Gate-users at lists.opengatecollaboration.org
>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
> 
> ----------------------------------------------------------------
> Didier BENOIT, GATE Engineer
> Imagerie et Modélisation en Neurobiologie et Cancérologie (IMNC)
> IMNC – UMR 8165 CNRS – Université Paris 7 – Université Paris 11
> Campus d’Orsay
> Bâtiment 440
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> 
> Tél : (33) 1 69 15 68 76
> E-mail : benoit at imnc.in2p3.fr
> http://www.imnc.in2p3.fr
> ----------------------------------------------------------------
> 
> 
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/----------------------------------------------------------------------
Prof. Dr. Uwe Pietrzyk
Diplom-Physiker
Institut für Neurowissenschaften und Medizin / INM-4
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&
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