[Gate-users] Re : Re: Re : Re: 64 Cu positron spectra problem

tienphong.pham at laposte.net tienphong.pham at laposte.net
Wed Mar 4 12:37:13 CET 2020


Hi Sofia,
I’ve done exactly as you said but it doesn’t seem to work. I still have the difference between the spectral ion source and spectral definition. 
This is my spectrum that I obtained ( please see the attached file)
Furthermore, I did test with the source ion F18 and then compared with spectral definition. Unfortunately, I’ve got the same problem as for the Cu64 source ion.
There are two sources that I tried: 
----------------------------------------------------------------------------------
/gate/source/addSource sourceF18
/gate/source/sourceF18/setActivity 1. MBq
/gate/source/sourceF18/gps/particle e+
/gate/source/sourceF18/setForcedUnstableFlag true
/gate/source/sourceF18/gps/energytype Fluor18
/gate/source/sourceF18/setForcedHalfLife 6586 s
/gate/source/sourceF18/gps/type Volume
/gate/source/sourceF18/gps/shape Sphere
/gate/source/sourceF18/gps/radius 1. mm
/gate/source/sourceF18/gps/centre 0. 0. 0. cm
/gate/source/sourceF18/gps/confine NULL 
/gate/source/sourceF18/gps/angtype iso
-------------------------------------------------------------------------------------
/gate/source/addSource fluor18
/gate/source/fluor18/setActivity 1. MBq
/gate/source/fluor18/gps/particle ion
/gate/source/fluor18/gps/ion 9 18 0 0 
/gate/source/fluor18/gps/energytype Mono
/gate/source/fluor18/gps/monoenergy 0. MeV
/gate/source/fluor18/gps/angtype iso
/gate/source/fluor18/gps/number 1
/gate/source/fluor18/gps/centre 0. 0. 0. cm
/gate/source/fluor18/gps/type Volume
/gate/source/fluor18/gps/shape Sphere
/gate/source/fluor18/gps/radius 1. mm
As far as I know, the difference between energy spectra of electron and positron can be explained by the fact that electron is attracted by the nucleus once it is created while the positron is repelled. So, I think I’m missing a model concerning coulomb interactions for the radioactive decay. I’m trying to look deeper into it, but I’ve yet to succeed. Maybe someone else has any other ideas to fix this problem?
Best regards,


----- Mail d'origine -----De: Sofia Kolovi <sofiaphys at gmail.com>À: tienphong pham <tienphong.pham at laposte.net>Cc: Matthew Strugari <matthew.strugari at dal.ca>, gate-users <gate-users at lists.opengatecollaboration.org>Envoyé: Mon, 02 Mar 2020 21:47:56 +0100 (CET)Objet: Re: [Gate-users] Re : Re: 64 Cu positron spectra problem


Hello,

First of all, concerning the last email, you put in your code
/gate/source/Cu64Source/gps/monoenergy          0. MeV
which generally means that you declare that your source emits 0 energy.
The colleague above suggested to insert
/gate/source/pointSource/gps/energy 0 MeV
in order to declare that your source has 0 kinetic energy.
 
Apart from that, you may try to see if there is a bug with the radioactive decay for this ion.
You can simply use the UserSpectrum (described in Source section of the documentation) where you describe on your own the energy spectrum emitted by your source and then compare with what you got using Radioactive Decay.
 
I hope you find this helpful,
Best regards,
Sofia



On Mon, 2 Mar 2020 at 20:40, <tienphong.pham at laposte.net> wrote:

Hi Matthew and Zhengzhi Liu,

Thank you very much for your quick response. I tried doing as you guys suggested but it still doesn't work. I don't know what's wrong yet.

Here is my code: 


#=====================================================# GEOMETRY#=====================================================
/gate/geometry/setMaterialDatabase data/GateMaterials.db
# World/gate/world/geometry/setXLength 1. m/gate/world/geometry/setYLength 1. m/gate/world/geometry/setZLength 1. m/gate/world/setMaterial Water
# Water Box/gate/world/daughters/name              phantom/gate/world/daughters/insert            box/gate/phantom/geometry/setXLength      20. cm/gate/phantom/geometry/setYLength      20. cm/gate/phantom/geometry/setZLength      20. cm/gate/phantom/placement/setTranslation 0. 0. 0. cm/gate/phantom/setMaterial Water/gate/phantom/vis/setVisible 1/gate/phantom/vis/setColor blue
#=====================================================# PHYSIC #=====================================================
/gate/physics/addPhysicsList emstandard_opt4 /gate/physics/addProcess RadioactiveDecay
#=====================================================# ACTOR#=====================================================
#===========Positron spectra=========================================================================
/gate/actor/addActor EnergySpectrumActor                      Pos_Spectrum/gate/actor/Pos_Spectrum/save                                 ./output/Pos_Spectrum.root/gate/actor/Pos_Spectrum/attachTo                           phantom/gate/actor/Pos_Spectrum/addFilter                            particleFilter/gate/actor/Pos_Spectrum/particleFilter/addParticle           e+/gate/actor/Pos_Spectrum/energySpectrum/setEmin               10 keV/gate/actor/Pos_Spectrum/energySpectrum/setEmax               1 MeV/gate/actor/Pos_Spectrum/energySpectrum/setNumberOfBins       1000/gate/actor/Pos_Spectrum/enableNbPartSpectrum true
#===========Positron spectra==========================================================================
#===========Beta Spectra==============================================================================
/gate/actor/addActor EnergySpectrumActor                      Beta_Spectrum/gate/actor/Beta_Spectrum/save                                ./output/Beta_Spectrum.root/gate/actor/Beta_Spectrum/attachTo                           phantom
/gate/actor/Beta_Spectrum/addFilter                           particleFilter/gate/actor/Beta_Spectrum/particleFilter/addParticle          e-
/gate/actor/Beta_Spectrum/energySpectrum/setEmin              10 keV/gate/actor/Beta_Spectrum/energySpectrum/setEmax              1 MeV/gate/actor/Beta_Spectrum/energySpectrum/setNumberOfBins      1000/gate/actor/Beta_Spectrum/enableNbPartSpectrum true
#===========Beta spectra=================================================================================
/gate/run/initialize
#=====================================================# Source#=====================================================
/gate/source/addSource                          Cu64Source gps/gate/source/Cu64Source/gps/particle            ion/gate/source/Cu64Source/gps/ion                 29 64 0 0/gate/source/Cu64Source/useDefaultHalfLife/gate/source/Cu64Source/setActivity             1. MBq/gate/source/Cu64Source/gps/energytype          Mono/gate/source/Cu64Source/gps/monoenergy          0. MeV/gate/source/Cu64Source/gps/angtype             iso/gate/source/Cu64Source/gps/centre              0. 0. 0. cm/gate/source/Cu64Source/gps/type                Volume/gate/source/Cu64Source/gps/shape               Sphere/gate/source/Cu64Source/gps/radius              1. mm
#=====================================================# MAIN#=====================================================
/gate/random/setEngineName MersenneTwister/gate/random/setEngineSeed 10
# PARTICLE/gate/application/setTotalNumberOfPrimaries 1000000/gate/application/start


Tell me, please, what i'm missing here?


Thank you again for your help.

Tien-Phong PHAM



----- Mail d'origine -----De: Matthew Strugari <matthew.strugari at dal.ca>À: Zhengzhi Liu <zliu36 at stanford.edu>, Tien-Phong PHAM <tienphong.pham at laposte.net>Cc: gate-users <gate-users at lists.opengatecollaboration.org>Envoyé: Mon, 02 Mar 2020 19:17:43 +0100 (CET)Objet: Re: [Gate-users] 64 Cu positron spectra problem

Hi Zhengzhi and Tien-Phong,

Please refer to https://opengate.readthedocs.io/en/latest/setting_up_the_physics.html# for information on physics list. The implementation suggested by Zhengzhi is being deprecated and should not be used. Rather, use the physics list builder mechanism:

/gate/physics/addPhysicsList emstandard_opt4
/gate/physics/addProcess RadioactiveDecay

You may replace emstandard_opt4 with the physics list builder most suitable for your needs (seehttp://geant4-userdoc.web.cern.ch/geant4-userdoc/UsersGuides/PhysicsListGuide/html/index.html for more info on physics lists.) Also, the following line may be required with your source definition to ensure that your Cu-64 source has no kinetic energy:

/gate/source/pointSource/gps/energy 0 MeV


Regards,
Matthew
 

From: Gate-users <gate-users-bounces at lists.opengatecollaboration.org> on behalf of Zhengzhi Liu <zliu36 at stanford.edu>Sent: March 2, 2020 1:22 PMTo: Tien-Phong PHAM <tienphong.pham at laposte.net>Cc: gate-users <gate-users at lists.opengatecollaboration.org>Subject: Re: [Gate-users] 64 Cu positron spectra problem
 


Hi Tien-Phong, 

Below is my physics.mac Could you compare this with yours? You might have missed something in your physics.mac. 

Good luck,
Zhengzhi 



#-------------------oooooOOOOO00000OOOOOooooo---------------------#

#                                                                 #

#             P H Y S I C A L   P R O C E S S E S                 #

#                                                                 #

#-------------------oooooOOOOO00000OOOOOooooo---------------------#

/gate/physics/addProcess PhotoElectric

/gate/physics/processes/PhotoElectric/setModel StandardModel

/gate/physics/addProcess Compton

/gate/physics/processes/Compton/setModel StandardModel

/gate/physics/addProcess RayleighScattering

/gate/physics/processes/RayleighScattering/setModel PenelopeModel

/gate/physics/addProcess ElectronIonisation

/gate/physics/processes/ElectronIonisation/setModel StandardModel e-

/gate/physics/processes/ElectronIonisation/setModel StandardModel e+

/gate/physics/addProcess Bremsstrahlung

/gate/physics/processes/Bremsstrahlung/setModel StandardModel e-

/gate/physics/processes/Bremsstrahlung/setModel StandardModel e+

/gate/physics/addProcess PositronAnnihilation

/gate/physics/addProcess eMultipleScattering e+

/gate/physics/addProcess eMultipleScattering e-

/gate/physics/processList Enabled

/gate/physics/processList Initialized

/gate/physics/addProcess IonIonisation

/gate/physics/addProcess RadioactiveDecay



On Mon, Mar 2, 2020 at 6:15 AM Tien-Phong PHAM <tienphong.pham at laposte.net> wrote:


Dear Gate-users,
I’m trying to simulate the energy spectrum of a Cu-64 source using the ion definition in GATE v8.2, but i have a problem with the positron emission spectra. In fact, the energy distribution with my ion source is very different with spectral definition in the low energy region. I mean the energy spectrum of positron is similar to the energy spectrum of electron.
In this case, i just used the « RadioactiveDecay » as physics list
I would like to ask if someone has experience with ion type source can help me.
Many thanks for your help !

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Gate-users mailing listGate-users at lists.opengatecollaboration.orghttp://lists.opengatecollaboration.org/mailman/listinfo/gate-users





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Gate-users mailing listGate-users at lists.opengatecollaboration.orghttp://lists.opengatecollaboration.org/mailman/listinfo/gate-users


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