[Gate-users] Ge68 source

[Marc Chamberland]

(Re-sent to include the Gate Users mailing list.)

Hi Shelley!

According to the Geant4 9.4 Physics Reference Manual, electron capture is included in radioactive decay (look at Chapter 37 in the PDF) : http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/PhysicsReferenceManual/BackupVersions/V9.4/fo/PhysicsReferenceManual.pdf

Also, if you look at the RadioactiveDecay data file for Ge-68 (z32.a68), you'll see the electron capture branching ratios is included.

As for the simulation time, my first suggestion would be to use the cluster tools included with Gate. If you don't have access to a computer cluster, maybe you can check if GateLab would work for you: http://www.opengatecollaboration.org/GateLab

Also, I'm no expert in PET, but couldn't you do attenuation correction simply with a back-to-back gamma source instead? This would be way faster. Of course, for your actual PET simulations you would use a more realistic source.

I hope this helps!

Marc



__________________________

Marc Chamberland, MSc
PhD candidate
Department of Physics
Carleton University
Ottawa (ON)

Le 2012-08-30 à 8:56 AM, Marc Chamberland <MarcChamberland at cmail.carleton.ca<mailto:MarcChamberland at cmail.carleton.ca>>
 a écrit :

Hi Shelley!

According to the Geant4 9.4 Physics Reference Manual, electron capture is included in radioactive decay (look at Chapter 37 in the PDF) : http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/PhysicsReferenceManual/BackupVersions/V9.4/fo/PhysicsReferenceManual.pdf

Also, if you look at the RadioactiveDecay data file for Ge-68 (z32.a68), you'll see the electron capture branching ratios is included.

As for the simulation time, my first suggestion would be to use the cluster tools included with Gate. If you don't have access to a computer cluster, maybe you can check if GateLab would work for you: http://www.opengatecollaboration.org/GateLab

Also, I'm no expert in PET, but couldn't you do attenuation correction simply with a back-to-back gamma source instead? This would be way faster. Of course, for your actual PET simulations you would use a more realistic source.

I hope this helps!

Marc



__________________________

Marc Chamberland, MSc
PhD candidate
Department of Physics
Carleton University
Ottawa (ON)

Le 2012-08-30 à 3:54 AM, xcao <xcao at mail.ihep.ac.cn<mailto:xcao at mail.ihep.ac.cn>>
 a écrit :

hi, Marc!

   Thank you for you reply.
   Yes, using "ion source" will solve this problem, I have tested, but should use Ga-68 instead of Ge-68.
I think the reason maybe the physical process of electron capture is not include. Even so, Ga-68 will be ok.

Another problem is what you have mentioned, using "ion source" will slow down simulations.
I want to using Ge-68 source to do attenuation correction on PET,  this will need plenty of data samples.
So simulation time is also very important. If you have any better suggestion for simulation time.

Thank you very much!
Shelley

2012-08-30
________________________________
xcao
________________________________
发件人： Marc Chamberland
发送时间： 2012-08-29  21:15:54
收件人： xcao
抄送： gate-users at lists.opengatecollaboration.org<mailto:gate-users at lists.opengatecollaboration.org>
主题： Re: [Gate-users] Ge68 source
Hi!
You can define a Ge-68 source in Gate by using the "ion source" type. See the documentation here: http://wiki.opengatecollaboration.org/index.php/Users_Guide_V6.1:Source#Defining_the_type_of_source
So for Ge-68, you would do it like this:
/gate/source/NAME/gps/particle ion
/gate/source/NAME/gps/ion 32 68 0 0
/gate/source/NAME/gps/monoenergy 0. keV
/gate/source/NAME/setForcedUnstableFlag true
/gate/source/NAME/setForcedHalfLife 23410080 s
You also need to add the RadioactiveDecay process in your physics list (before initialization):
/gate/physics/addProcess RadioactiveDecay
Note that using an ion source will slow down your simulations.
Cheers!
Marc
__________________________
Marc Chamberland, MSc
PhD candidate
Department of Physics
Carleton University
Ottawa (ON)
Le 2012-08-28 à 10:40 PM, xcao <xcao at mail.ihep.ac.cn<mailto:xcao at mail.ihep.ac.cn>>
 a écrit :
> hello, gate-users
>
>    If anyone have used the source of germanium-68, I want to know how to define it.
> Can anyone offer me some help.
>
> Thank you very much!
>
> 2012-08-29
>
>
>
> xcao
> _______________________________________________
> Gate-users mailing list
> Gate-users at lists.opengatecollaboration.org<mailto:Gate-users at lists.opengatecollaboration.org>
> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>