<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Dear Gate user's,<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>I have been working on understanding the phase space actor and I have a question maybe someone can help me with:<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>I modeled a cell with water in which there is a cluster of nanoparticles.<br data-mce-bogus="1"></div><div>I send a 150 keV gamma beam directly on the cluster and throught two phase space actors I'm looking at the different kinds of particles:<br data-mce-bogus="1"></div><div>- enterring the cluster and<br data-mce-bogus="1"></div><div>- produced inside the cluster.<br data-mce-bogus="1"></div><div>(1) As the cell is full of water I'm expecting more compton electrons <span style="text-decoration: underline;" data-mce-style="text-decoration: underline;">enterring the cluster</span> than photo-electric electrons.<br data-mce-bogus="1"></div><div>(2) Conversely, as my nanoparticles contains bismuth and gadolinium, I'm expecting more photo-electric electrons than compton electrons <span style="text-decoration: underline;" data-mce-style="text-decoration: underline;">produced inside</span> the cluster.<br data-mce-bogus="1"></div><div>I do observe (2) but I observe (1) only up to 5³ nanoparticles. From 15³ nanoparticles I have more photo-electric electrons enterring the cluster than compton electrons.... I do not understand this results.<br data-mce-bogus="1"></div><div>The number of nanoparticles in the cluster should not influence the electrons produced in water before reaching the cluster.... Am I misunderstanding the way the phase space actor works ?<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>If someone as an idea, many thanks for the help!<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Sarah Blind<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Here are my scripts:</div><div><br data-mce-bogus="1"></div><blockquote><div><strong>world.mac</strong><br data-mce-bogus="1"></div><div><br><br>/gate/geometry/setMaterialDatabase ../data/GateMaterials.db<br><br>/gate/world/geometry/setXLength 50 um<br>/gate/world/geometry/setYLength 50 um<br>/gate/world/geometry/setZLength 50 um<br>/gate/world/setMaterial Air<br><br>/gate/world/daughters/name cell<br>/gate/world/daughters/insert sphere<br>/gate/cell/geometry/setRmin 0.0 mm<br>/gate/cell/geometry/setRmax 10 um<br>/gate/cell/placement/setTranslation 0 0 0 cm<br>/gate/cell/setMaterial G4_WATER<br>/gate/cell/vis/setVisible 1<br>/gate/cell/vis/setColor blue<br>/gate/cell/vis/forceSolid false<br><br>/gate/cell/daughters/name nucleus<br>/gate/cell/daughters/insert sphere<br>/gate/nucleus/geometry/setRmin 0.0 mm<br>/gate/nucleus/geometry/setRmax 1 um<br>/gate/nucleus/placement/setTranslation 0 0 0 cm<br>/gate/nucleus/setMaterial G4_WATER<br>/gate/nucleus/vis/setVisible 1<br>/gate/nucleus/vis/setColor blue<br>/gate/nucleus/vis/forceSolid true<br><br>/gate/cell/daughters/name cluster<br>/gate/cell/daughters/insert sphere<br>/gate/cluster/geometry/setRmin 0.0 mm<br>/gate/cluster/geometry/setRmax 150 nm<br>/gate/cluster/placement/setTranslation -5 -6 0 um<br>/gate/cluster/setMaterial G4_WATER<br>/gate/cluster/vis/setVisible 1<br>/gate/cluster/vis/setColor green<br>/gate/cluster/vis/forceSolid false<br> <br>/gate/cluster/daughters/name NP<br>/gate/cluster/daughters/insert sphere<br>/gate/NP/geometry/setRmin 0 mm<br>/gate/NP/geometry/setRmax 2 nm<br>/gate/NP/placement/setTranslation 0 0 0 mm<br>/gate/NP/setMaterial AGuIX_65_35<br>/gate/NP/vis/setVisible 1<br>/gate/NP/vis/setColor red<br>/gate/NP/vis/forceSolid true<br><br>/gate/NP/repeaters/insert cubicArray<br>/gate/NP/cubicArray/setRepeatNumberX 15<br>/gate/NP/cubicArray/setRepeatNumberY 15<br>/gate/NP/cubicArray/setRepeatNumberZ 15<br>/gate/NP/cubicArray/setRepeatVector 4.5 4.5 4.5 nm<br><br><br><br></div><div><strong>source.mac</strong><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>/gate/source/addSource mybeam gps<br>/gate/source/mybeam/gps/particle gamma<br>/gate/source/mybeam/gps/ene/type User<br>/gate/source/mybeam/gps/hist/type energy<br><br>[historgram]<br><br>/gate/source/mybeam/gps/position -5 20000 0 um<br>/gate/source/mybeam/gps/pos/type Volume<br>/gate/source/mybeam/gps/pos/shape Cylinder<br>/gate/source/mybeam/gps/pos/inner_radius 0 nm<br>/gate/source/mybeam/gps/pos/radius 150 nm<br>/gate/source/mybeam/gps/pos/halfz 150 nm<br>/gate/source/mybeam/gps/ang/type beam2d<br><br>/gate/source/mybeam/gps/ang/rot1 0 0 1 <br>/gate/source/mybeam/gps/ang/rot2 1 0 0 <br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><strong>physics.mac</strong><br><br># Geant4-DNA<br>/gate/physics/addPhysicsListMixed emstandard_opt3_mixed_emdna<br>/gate/physics/SetDNAInRegion nucleus<br>/gate/physics/ConstructProcessMixed<br><br>/gate/physics/Electron/SetCutInRegion world 1 mm<br>/gate/physics/Gamma/SetCutInRegion world 1 mm<br><br>/gate/physics/Electron/SetCutInRegion cell 10 nm<br>/gate/physics/Gamma/SetCutInRegion cell 0.1 mm</div><div><br>/gate/physics/displayCuts<br><br>/gate/physics/addAtomDeexcitation<br><br>/gate/physics/addProcess PhotoElectric gamma<br>/gate/physics/processes/PhotoElectric/setModel LivermoreModel<br>/gate/physics/processes/PhotoElectric/setAugerElectron true<br>/gate/physics/processes/PhotoElectric/setDeltaRayCut 10 eV<br>/gate/physics/processes/PhotoElectric/setXRayCut 10 eV<br>/gate/physics/processes/PhotoElectric/setStepFunction e- 0.2 0.1 nm<br><br>/gate/physics/addProcess Compton gamma<br>/gate/physics/processes/Compton/setModel LivermoreModel<br>/gate/physics/processes/Compton/setStepFunction e- 0.2 0.1 nm<br><br>/gate/physics/addProcess GammaConversion<br>/gate/physics/processes/GammaConversion/setModel LivermoreModel<br><br>/gate/physics/addProcess ElectronIonisation<br>/gate/physics/processes/ElectronIonisation/setModel LivermoreModel e-<br>/gate/physics/processes/ElectronIonisation/setStepFunction e- 0.2 0.1 nm<br><br>/gate/physics/addProcess Bremsstrahlung e-<br>/gate/physics/addProcess Bremsstrahlung e+<br>/gate/physics/processes/Bremsstrahlung/setModel LivermoreModel e-<br>/gate/physics/processes/Bremsstrahlung/setModel PenelopeModel e+<br><br>/gate/physics/addProcess eMultipleScattering e-<br>/gate/physics/addProcess eMultipleScattering e+<br>/gate/physics/processes/eMultipleScattering/setModel UrbanModel e-<br>/gate/physics/processes/eMultipleScattering/setModel UrbanModel e+<br><br>/gate/physics/SetMinKineticEnergyInRegion world 8 eV<br>/gate/physics/SetMinKineticEnergyInRegion cell 8 eV<br>/gate/physics/ActivateSpecialCuts gamma<br><br><br data-mce-bogus="1"></div><div><strong>detecors.mac</strong></div><div><br>/gate/actor/addActor DoseActor doseDistribution<br>/gate/actor/doseDistribution/save output/doseActor.hdr<br>/gate/actor/doseDistribution/attachTo cluster<br>/gate/actor/doseDistribution/stepHitType random<br>/gate/actor/doseDistribution/setPosition 0 0 0 cm<br>/gate/actor/doseDistribution/setVoxelSize 1 1 1 nm<br>/gate/actor/doseDistribution/enableEdep true<br>/gate/actor/doseDistribution/enableUncertaintyEdep true<br>/gate/actor/doseDistribution/enableDose true<br>/gate/actor/doseDistribution/enableNumberOfHits false<br><br>/gate/actor/addActor PhaseSpaceActor phaseSpace_NP_entry<br>/gate/actor/phaseSpace_NP_entry/save output/phaseSpaceNP_entry.root<br>/gate/actor/phaseSpace_NP_entry/attachTo cluster<br>/gate/actor/phaseSpace_NP_entry/enableProductionProcess true<br>/gate/actor/phaseSpace_NP_entry/storeSecondaries false<br>/gate/actor/phaseSpace_NP_entry/storeOutgoingParticles false<br><br><br>/gate/actor/addActor PhaseSpaceActor phaseSpace_NP_IN<br>/gate/actor/phaseSpace_NP_IN/save output/phaseSpaceNP_IN.root<br>/gate/actor/phaseSpace_NP_IN/attachTo cluster<br>/gate/actor/phaseSpace_NP_IN/enableProductionProcess true<br>/gate/actor/phaseSpace_NP_IN/enableTrackLength true<br>/gate/actor/phaseSpace_NP_IN/storeSecondaries true<br><br><br><br data-mce-bogus="1"></div></blockquote><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div></div></body></html>