[Gate-users] Why Y90 has different energy distributions when using ion source and fastY90 source?
Carlier Thomas
thomas.carlier at chu-nantes.fr
Tue Jan 24 14:24:10 CET 2017
Dear all,
We look with Jared (the developer of fast90Y) your simulation set-up.
Two remarks:
1 - The ion source related to 90Y do not include the internal pair
creation. Be aware of that because you are looking something close to
the conventional PET energy window. So, when you want to make a
comparison, please add a corresponding positron source to the ion source
2 - The use of the fast90Y needs to add about 5 mm of padding past the
edges of the Y90 source so that brem could be created. Otherwise, a lot
of electrons will be emitted in air next to the phantom. This is a small
difference but take care of that..
Lastly, the energy distribution of the brem used in the fast Y90 model
is derived from the ion source simulation. Hence, it is not expected to
have big difference between the two...
Hope this help
Thomas Carlier
University hospital of Nantes
Nuclear Medicine Dept
France
Le 24/01/2017 à 09:48, Jinxia Guo a écrit :
> Paulo,
>
> The phantom and source size didn't have effects on the energy
> distributions. I checked the physic interactions in the hits data.
> PhotonElectric, RayleighScatter and ComptonScatter were found in
> fastY90 simulation. Besides these three, plenty of ElectricIonization
> and Bremsstrahlung were also found in ion source simultions. These two
> kinds of interaction in crystals may be the reason of the difference
> in the energy distributions. Maybe they were forbidden in fastY90 source.
>
>
> Anyway, thanks!
>
> Jinxia
>
> 2017-01-24 0:35 GMT+08:00 Paulo Caribé <Paulo.Caribe at ugent.be
> <mailto:Paulo.Caribe at ugent.be>>:
>
> Jinxia,
>
> make sure that your phantom and source are in the same size. Have
> you tried it in this away?
>
> 1）Setting1: simulation with fastY90
>
> #-----------------Phantom--------------------------------
>
> /gate/cylinder_phantom/geometry/setHeight 30.5 cm (You should put
> setHeight = 30.065 cm)
>
> #-----------------Source--------------------------------
>
> /gate/source/ionsrc/gps/halfz 15.0325 cm
>
> ##########################################
>
>
> 2）Setting2: simulation with the ion source
>
> #-----------------Phantom--------------------------------
>
> /gate/cylinder_phantom/geometry/setHeight30.065 cm
>
> #-----------------Source--------------------------------
>
> /gate/source/ionsrc/gps/halfz 15.0325 cm
>
> ##########################################################
>
> Regards,
>
> Doctoral researcher
> Ghent University - iMinds Medical IT
> Medical Imaging and Signal Processing (MEDISIP)
> IBiTech - Campus UZ - Entrance 36 (Block B)
> De Pintelaan 185
> B-9000 Gent
> Belgium
>
>
>
>> On 23 Jan 2017, at 15:30, Jinxia Guo <jinxia.guo2009 at gmail.com
>> <mailto:jinxia.guo2009 at gmail.com>> wrote:
>>
>> Hi guys,
>>
>>
>> Recently I’ve done some simulation with Y90 source in Gate7.2
>> develop version. Two settings are with the same camera, digitizer
>> and output but respectively with normal ion source and fastY90
>> source. The energy distributions of singles in coincidences for
>> each setting are shown below. It seems that the energy
>> distribution with the normal ion source is very different with
>> the fastY90 source. I thought they should be the same, but why
>> the results actually are not? Anything wrong in the simulations
>> setting? Thanks!
>>
>>
>> *The energy distributions of each setting.*
>>
>> (1) fastY90 source (energy window: [420, inf]) (2)
>> ion source (energy window:[420, inf])
>>
>>
>> (3) fastY90 source (energy window: [0, inf])
>> (4) ion source (energy window:[0, inf])
>>
>>
>>
>> （1）Setting1: simulation with fastY90
>>
>> #-----------------Phantom--------------------------------
>>
>> /gate/world/daughters/name cylinder_phantom
>>
>> /gate/world/daughters/insert cylinder
>>
>> /gate/cylinder_phantom/setMaterial Water
>>
>> /gate/cylinder_phantom/geometry/setRmax 10 cm
>>
>> /gate/cylinder_phantom/geometry/setRmin 0 cm
>>
>> /gate/cylinder_phantom/geometry/setHeight 30.5 cm
>>
>> /gate/cylinder_phantom/placement/setTranslation 0. 0. 0. mm
>>
>> /gate/cylinder_phantom/attachPhantomSD
>>
>>
>> #-----------------Source--------------------------------
>>
>> /gate/source/addSource ionsrc fastY90
>>
>> /gate/source/ionsrc/setActivity 0.1 Ci
>>
>> /gate/source/ionsrc/useDefaultHalfLife
>>
>> /gate/source/ionsrc/gps/angtype iso
>>
>> /gate/source/ionsrc/gps/number 1
>>
>>
>> /gate/source/ionsrc/setMinBremEnergy 50 keV
>>
>> /gate/source/ionsrc/setPositronProbability 0.00003186
>>
>>
>> /gate/source/ionsrc/gps/type Volume
>>
>> /gate/source/ionsrc/gps/shape Cylinder
>>
>> /gate/source/ionsrc/gps/radius 10 cm
>>
>> /gate/source/ionsrc/gps/halfz 15.0325 cm
>>
>> /gate/source/ionsrc/gps/centre 0. 0. 0. Mm
>>
>> /gate/source/ionsrc/gps/confine cylinder_phantom
>>
>>
>> #-----------------Physics--------------------------------
>>
>> /gate/physics/addProcess Decay
>>
>> /gate/physics/addProcess RadioactiveDecay
>>
>>
>> /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 MultipleScattering e+
>>
>> /gate/physics/addProcess MultipleScattering e-
>>
>>
>> /gate/physics/setEMin 0.1 keV
>>
>> /gate/physics/setEMax 2.0 GeV
>>
>> /gate/physics/setDEDXBinning 220
>>
>> /gate/physics/setLambdaBinning 220
>>
>>
>> /gate/physics/processList Enabled
>>
>> /gate/physics/processList Initialized
>>
>>
>> （2）Setting2: simulation with the ion source
>>
>> #-----------------Phantom--------------------------------
>>
>> /gate/world/daughters/name cylinder_phantom
>>
>> /gate/world/daughters/insert cylinder
>>
>> /gate/cylinder_phantom/setMaterial Water
>>
>> /gate/cylinder_phantom/geometry/setRmax 10 cm
>>
>> /gate/cylinder_phantom/geometry/setRmin 0 cm
>>
>> /gate/cylinder_phantom/geometry/setHeight 30.065 cm
>>
>> /gate/cylinder_phantom/placement/setTranslation 0. 0. 0. mm
>>
>> /gate/cylinder_phantom/attachPhantomSD
>>
>>
>> #-----------------Source--------------------------------
>>
>> /gate/source/addSource ionsrc
>>
>> /gate/source/ionsrc/setActivity 0.10 Ci
>>
>> /gate/source/ionsrc/gps/particle ion
>>
>> /gate/source/ionsrc/gps/ion 39 90 0 0
>>
>> /gate/source/ionsrc/setForcedUnstableFlag true
>>
>> #/gate/source/ionsrc/setForcedHalfLife 230544 s
>>
>> /gate/source/ionsrc/useDefaultHalfLife
>>
>> /gate/source/ionsrc/gps/angtype iso
>>
>> /gate/source/ionsrc/gps/number 1
>>
>>
>> /gate/source/ionsrc/gps/type Volume
>>
>> /gate/source/ionsrc/gps/shape Cylinder
>>
>> /gate/source/ionsrc/gps/radius 10 cm
>>
>> /gate/source/ionsrc/gps/halfz 15.0325 cm
>>
>> /gate/source/ionsrc/gps/centre 0. 0. 0. mm
>>
>>
>> /gate/source/ionsrc/gps/confine cylinder_phantom
>>
>>
>> #-----------------Physics--------------------------------
>>
>> /gate/physics/addProcess Decay
>>
>> /gate/physics/addProcess RadioactiveDecay
>>
>>
>> /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 GammaConversion
>>
>> /gate/physics/processes/GammaConversion/setModel StandardModel
>>
>>
>> /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 MultipleScattering e+
>>
>> /gate/physics/addProcess MultipleScattering e-
>>
>>
>> /gate/physics/setEMin 0.1 keV
>>
>> /gate/physics/setEMax 2.0 GeV
>>
>> /gate/physics/setDEDXBinning 220
>>
>> /gate/physics/setLambdaBinning 220
>>
>>
>> /gate/physics/processList Enabled
>>
>> /gate/physics/processList Initialized
>>
>>
>>
>>
>>
>> Regards,
>>
>> Jinxia
>>
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