[Gate-users] Bug when using RadioactiveDecay in GATE 7.1

Jared Strydhorst jared.strydhorst at gmail.com
Tue Sep 15 16:31:59 CEST 2015


Hi Uwe,
What matters is the version of Geant4, and Dennis Wright, who's responsible
for the RadioactiveDecay module, confirmed that the bug is present in
versions 10.1 patch 1 and patch 2. Maybe it's not present in the original
release of 10.1? I don't have the unpatched 10.1 to test it. I know the
decay worked correctly with Geant4 version 9.6.3.

Jared

2015-09-15 16:12 GMT+02:00 Pietrzyk, Uwe <u.pietrzyk at fz-juelich.de>:

>
> Hi Jared,
>
> thanks for sending the additional infos. Do you eventually
> know wether the combination Gate_7.1 & Geant4-10-1
> is also affected? This is what I advised to use on my Mac.
>
> Many thanks and kind regards,
>
> Uwe
>
> /----------------------------------------------------------------------
> Prof. Dr. Uwe Pietrzyk
> Diplom-Physiker
> Institut für Neurowissenschaften und Medizin / INM-4
> Forschungszentrum Jülich GmbH
> 52425 Jülich
> Tel: +49-2461-61 4763
> Fax: +49-2461-61 2820
> Mobil: +49-162-103-4871
> eMail: U.Pietrzyk at fz-juelich.de
> http://www.fz-juelich.de/inm/inm-4/DE/Home/home_node.html
> &
> Bergische Universität Wuppertal
> Fachbereich C - Physik / D.08.01
> Gaußstr. 20
> 42097 Wuppertal
> Tel: +49-(0)202-439-3523
> Fax: +49-(0)202-439-2811
> eMail: Uwe.Pietrzyk at physik.uni-wuppertal.de
> http://www.medizinphysik.uni-wuppertal.de
> ----------------------------------------------------------------------/
>
> On 15 Sep 2015, at 11:38, Jared Strydhorst <jared.strydhorst at gmail.com>
> wrote:
>
> When I originally encountered the problem while simulating just the LSO
> contribution to a PET system, I noticed that there was only a single peak
> around 300 keV, and none near 200 keV. I wrote a test simulation, attached,
> with not detector, but that simulates a single decay of Lu176. If you look
> at the verbose output produced with v7.0 vs. v7.1, the difference in the
> decay is apparent. I've excerpted the relevant portions of the output below.
>
> GATE 7.0
> ========================================================================
>
>
> *********************************************************************************************************
> * G4Track Information:   Particle = Hf176[597.0],   Track ID = 2,   Parent
> ID = 1
>
> *********************************************************************************************************
>
> Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
> NextVolume ProcName
>     0        0        0        0  1.96e-06        0        0         0
> world_phys initStep
>     1 -0.000751 -0.000973 0.000396         0 1.96e-06  0.00129   0.00129
> world_phys ionIoni
>     2 -0.000751 -0.000973 0.000396         0        0        0   0.00129
> world_phys RadioactiveDecay
>     :----- List of 2ndaries - #SpawnInStep=  2(Rest= 2,Along= 0,Post= 0),
> #SpawnTotal=  2 ---------------
>     : -0.000751 -0.000973  0.000396         0       Hf176[290.2]
>     : -0.000751 -0.000973  0.000396     0.307              gamma
>     :-----------------------------------------------------------------
> EndOf2ndaries Info ---------------
>
>
> *********************************************************************************************************
> * G4Track Information:   Particle = Hf176[290.2],   Track ID = 12,
> Parent ID = 2
>
> *********************************************************************************************************
>
> Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
> NextVolume ProcName
>     0 -0.000751 -0.000973 0.000396         0        0        0         0
> world_phys initStep
>     1 -0.000751 -0.000973 0.000396         0        0        0         0
> world_phys RadioactiveDecay
>     :----- List of 2ndaries - #SpawnInStep=  2(Rest= 2,Along= 0,Post= 0),
> #SpawnTotal=  2 ---------------
>     : -0.000751 -0.000973  0.000396         0        Hf176[88.4]
>     : -0.000751 -0.000973  0.000396     0.202              gamma
>     :-----------------------------------------------------------------
> EndOf2ndaries Info ---------------
>
> *********************************************************************************************************
> * G4Track Information:   Particle = Hf176[88.4],   Track ID = 14,   Parent
> ID = 12
>
> *********************************************************************************************************
>
> Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
> NextVolume ProcName
>     0 -0.000751 -0.000973 0.000396         0        0        0         0
> world_phys initStep
>     1 -0.000751 -0.000973 0.000396         0        0        0         0
> world_phys RadioactiveDecay
>     :----- List of 2ndaries - #SpawnInStep=  5(Rest= 5,Along= 0,Post= 0),
> #SpawnTotal=  5 ---------------
>     : -0.000751 -0.000973  0.000396         0         Hf176[0.0]
>     : -0.000751 -0.000973  0.000396   0.00162                 e-
>     : -0.000751 -0.000973  0.000396   0.00789              gamma
>     : -0.000751 -0.000973  0.000396    0.0559              gamma
>     : -0.000751 -0.000973  0.000396    0.0231                 e-
>     :-----------------------------------------------------------------
> EndOf2ndaries Info ---------------
>
>
>
> GATE 7.1
> ===========================================================================
>
>
> *********************************************************************************************************
> * G4Track Information:   Particle = Hf176[596.820],   Track ID = 2,
> Parent ID = 1
>
> *********************************************************************************************************
>
> Step#    X(mm)    Y(mm)    Z(mm) KinE(MeV)  dE(MeV) StepLeng TrackLeng
> NextVolume ProcName
>     0        0        0        0  2.88e-07        0        0         0
> world_phys initStep
>     1 -9.46e-309 -3.16e-309 -9.73e-309         0 2.88e-07 1.39e-308
> 1.39e-308  world_phys RadioactiveDecay
>     :----- List of 2ndaries - #SpawnInStep=  3(Rest= 0,Along= 0,Post= 3),
> #SpawnTotal=  3 ---------------
>     : -9.46e-309 -3.16e-309 -9.73e-309         0              Hf176
>     : -9.46e-309 -3.16e-309 -9.73e-309      0.29              gamma
>     : -9.46e-309 -3.16e-309 -9.73e-309     0.307              gamma
>     :-----------------------------------------------------------------
> EndOf2ndaries Info ---------------
>
>
> Jared
>
>
> ============================Lu176_test.mac===================================
> # VISUALIZATION
> /vis/open OGLSX
> /vis/viewer/reset
> /vis/viewer/set/viewpointThetaPhi 20 30
> /vis/viewer/set/style surface
> /vis/drawVolume
>
> /tracking/storeTrajectory 1
> /vis/scene/endOfEventAction accumulate
> /vis/viewer/update
>
> /vis/scene/add/trajectories
>
> /gate/geometry/setMaterialDatabase GateMaterials.db
>
> # WORLD
> /gate/world/geometry/setXLength 4. cm
> /gate/world/geometry/setYLength 4. cm
> /gate/world/geometry/setZLength 4. cm
> /gate/world/setMaterial Air
> /gate/world/vis/forceWireframe
>
> /gate/geometry/rebuild
>
> # PHYSICS
> /gate/physics/addPhysicsList emstandard_opt3
> /gate/physics/addProcess RadioactiveDecay GenericIon
> #/gate/physics/addProcess IonIonisation      GenericIon
>
> # INITIALIZATION
> /gate/run/initialize
>
> /gate/source/addSource Lu176
> /gate/source/Lu176/setActivity 1 Bq
> /gate/source/Lu176/gps/particle ion
> /gate/source/Lu176/gps/ion 71 176 0 0
> /gate/source/Lu176/gps/energytype Mono
> /gate/source/Lu176/gps/energy 0 MeV
> /gate/source/Lu176/gps/type Point
> /gate/source/Lu176/gps/centre 0. 0. 0. cm
> /gate/source/Lu176/gps/angtype iso
>
> # OUTPUT
> /gate/output/allowNoOutput
>
> /tracking/verbose 2
>
> /gate/random/setEngineName    MersenneTwister
> /gate/random/setEngineSeed    auto
>
> /gate/application/SetNumberOfPrimariesPerRun    1
> /gate/application/start
>
> ===========================================================================
>
> 2015-09-15 11:16 GMT+02:00 Pietrzyk, Uwe <u.pietrzyk at fz-juelich.de>:
>
>>
>> Hi Jared,
>>
>> let me briefly ask what the detector looked like?
>> Since there are emission lines of 202 and 88 keV, the 290 keV
>> is likely to be a "summation peak”.
>>
>> I have checked the RadioactiveDecay in 7.1 for our EduGATE
>> examples and did not find anything wrong. So I am a little bit
>> puzzled by the statements in your eMail.
>>
>> Kind regards,
>>
>> Uwe Pietrzyk
>>
>> /----------------------------------------------------------------------
>> Prof. Dr. Uwe Pietrzyk
>> Diplom-Physiker
>> Institut für Neurowissenschaften und Medizin / INM-4
>> Forschungszentrum Jülich GmbH
>> 52425 Jülich
>> Tel: +49-2461-61 4763
>> Fax: +49-2461-61 2820
>> Mobil: +49-162-103-4871
>> eMail: U.Pietrzyk at fz-juelich.de
>> http://www.fz-juelich.de/inm/inm-4/DE/Home/home_node.html
>> &
>> Bergische Universität Wuppertal
>> Fachbereich C - Physik / D.08.01
>> Gaußstr. 20
>> 42097 Wuppertal
>> Tel: +49-(0)202-439-3523
>> Fax: +49-(0)202-439-2811
>> eMail: Uwe.Pietrzyk at physik.uni-wuppertal.de
>> http://www.medizinphysik.uni-wuppertal.de
>> ----------------------------------------------------------------------/
>>
>> On 15 Sep 2015, at 11:05, Jared Strydhorst <jared.strydhorst at gmail.com>
>> wrote:
>>
>> If you're using RadioactiveDecay with GATE 7.1, there is a bug in Geant4
>> v10.1.1 that causes the emissions from the nuclear de-excitation to be
>> simulated incorrectly. For example, I've found that after Lu-176 decays to
>> Hf-176, it emits a 307 keV gamma, correctly, but then goes to the ground
>> state by emitting an unphysical 290 keV gamma, instead of a 202 keV
>> followed by a 88 keV gamma, or the competing conversion electrons. I don't
>> know how other isotopes are affected, though it seems from the relevant
>> Geant4 forum that the problem isn't specific to Hf de-excitation.
>>
>> The bug has been fixed in G4 v10.2 (still in beta), and doesn't seem to
>> be present in earlier versions, so if you use GATE 7.0 or earlier it
>> shouldn't affect you.
>>
>> 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
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>>
>>
>>
>>
>>
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>>
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>>
>
>
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