<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Dear Gate users,<br></div><div><br data-mce-bogus="1"></div><div>I want to model a spheroid which contains 30 000 cells in each of which there are 10 clusters of 10 nanoparticles.<br data-mce-bogus="1"></div><div>The composition of my nanoparticles is the following<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><blockquote><div> +el: name=Gadolinium ; f=0.15<br> +el: name=Silicon ; f=0.10<br> +el: name=Carbon ; f=0.25<br> +el: name=Nitrogen ; f=0.08<br> +el: name=Oxygen ; f=0.22<br> +el: name=Hydrogen ; f=0.20<br data-mce-bogus="1"></div></blockquote><div><br data-mce-bogus="1"></div><div>My spheroid, the cells and the clusters are all spheres full with water.</div><div>For the moment, what I'm trying to observe is very simple : <strong>with</strong> and <strong>without</strong> the nanoparticles (and thus only water) I should observe a difference, shouldn't I ?<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>I use Geant4-DNA; with 10 000 000 photons sent ; here is what my .hdr outpout file looks like</div><div><br data-mce-bogus="1"></div><div><table style="width: 16.2672%; height: 54px;" data-mce-style="width: 90%;" cellpadding="3px" border="1px"><tbody><tr style="height: 18px;"><td style="width: 1.18203%; height: 18px;">Nanoparticles<br></td><td style="width: 4.63031%; height: 18px;">Average in Gy<br></td></tr><tr style="height: 18px;"><td style="width: 1.18203%; height: 18px;">No<br></td><td style="width: 4.63031%; height: 18px;">0.002<br></td></tr><tr style="height: 18px;"><td style="width: 1.18203%; height: 18px;">Yes<br></td><td style="width: 4.63031%; height: 18px;"><div>0.001</div></td></tr></tbody></table><p>There is almost no difference between with and without the nanoparticles, this surprises me.<br data-mce-bogus="1"></p><p>I'm not a physicist, do you find this normal ?<br data-mce-bogus="1"></p><p>Here is my Gate code :<br data-mce-bogus="1"></p><p><br data-mce-bogus="1"></p><blockquote><p>======= world.mac =======<br><br><br>/gate/world/geometry/setXLength 0.5 cm<br>/gate/world/geometry/setYLength 0.5 cm<br>/gate/world/geometry/setZLength 0.5 cm<br>/gate/world/setMaterial Air<br><br><br>/gate/world/daughters/name <strong>spheroide</strong><br>/gate/world/daughters/insert sphere<br>/gate/spheroide/geometry/setRmin 0.0 mm<br>/gate/spheroide/geometry/setRmax 400 um<br>/gate/spheroide/placement/setTranslation 0 0 0 mm<br>/gate/spheroide/setMaterial G4_WATER<br>/gate/spheroide/vis/setVisible 1<br>/gate/spheroide/vis/setColor blue<br>/gate/spheroide/vis/forceSolid false<br><br><br>/gate/spheroide/daughters/name <strong>cell</strong><br>/gate/spheroide/daughters/insert sphere<br>/gate/cell/geometry/setRmin 0.0 mm<br>/gate/cell/geometry/setRmax 10 um<br>/gate/cell/placement/setTranslation 100 0 0 um<br>/gate/cell/setMaterial G4_WATER<br>/gate/cell/vis/setVisible 1<br>/gate/cell/vis/setColor green<br>/gate/cell/vis/forceSolid false<br><br>/gate/cell/daughters/name <strong>cluster</strong><br>/gate/cell/daughters/insert sphere<br>/gate/cluster/geometry/setRmin 0 mm<br>/gate/cluster/geometry/setRmax 0.05 um<br>/gate/cluster/placement/setTranslation 0 0 0 mm<br>/gate/cluster/setMaterial G4_WATER<br>/gate/cluster/vis/setVisible 1<br>/gate/cluster/vis/setColor yellow<br>/gate/cluster/vis/forceSolid false<br><br>/gate/cluster/daughters/name <strong>NP</strong><br>/gate/cluster/daughters/insert sphere<br>/gate/NP/geometry/setRmin 0 mm<br>/gate/NP/geometry/setRmax 0.004 um<br>/gate/NP/placement/setTranslation 0 0 0 mm<br>/gate/NP/setMaterial AGuIX<br>/gate/NP/vis/setVisible 1<br>/gate/NP/vis/setColor red<br>/gate/NP/vis/forceSolid true<br><br>### repeaters ### <br><br>/gate/NP/repeaters/insert genericRepeater<br>/gate/NP/genericRepeater/setPlacementsFilename ../data/NP.placements<br>/gate/NP/genericRepeater/useRelativeTranslation 1<br><br>/gate/cluster/repeaters/insert genericRepeater<br>/gate/cluster/genericRepeater/setPlacementsFilename ../data/cluster.placements<br>/gate/cluster/genericRepeater/useRelativeTranslation 1<br><br><br>/gate/cell/repeaters/insert cubicArray<br>/gate/cell/cubicArray/setRepeatNumberX 32<br>/gate/cell/cubicArray/setRepeatNumberY 32<br>/gate/cell/cubicArray/setRepeatNumberZ 32<br>/gate/cell/cubicArray/setRepeatVector 20 20 20 um<br><br></p><p>======= physics.mac =======<br></p><p><br># Geant4-DNA<br>/gate/physics/addPhysicsListMixed emstandard_opt3_mixed_emdna<br>/gate/physics/SetDNAInRegion spheroide<br>/gate/physics/ConstructProcessMixed<br><br>/gate/physics/Gamma/SetCutInRegion world 0.5 mm<br>/gate/physics/Electron/SetCutInRegion world 0.5 mm<br>/gate/physics/Positron/SetCutInRegion world 0.5 mm<br><br>/gate/physics/displayCuts<br><br># Choice of pseudo-random number generation algorithm<br>/gate/random/setEngineName MersenneTwister <br><br># Auger electron activation <br>/gate/physics/addAtomDeexcitation<br><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 RayleighScattering<br>/gate/physics/processes/RayleighScattering/setModel LivermoreModel<br><br># transformation of a photon into an electron-positron pair<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/setModel PenelopeModel 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+</p><p><br data-mce-bogus="1"></p><p>======= detectors.mac =======<br></p><p><br data-mce-bogus="1"></p><p>/gate/actor/addActor DoseActor dose<br>/gate/actor/dose/save output/dose.hdr<br>/gate/actor/dose/attachTo spheroide<br>/gate/actor/dose/stepHitType random<br>/gate/actor/dose/setPosition 0.0 0.0 0.0 mm<br>/gate/actor/dose/setSize 800 800 800 um<br>/gate/actor/dose/setResolution 400 400 400<br>/gate/actor/dose/enableDose true<br>/gate/actor/dose/saveEveryNSeconds 30</p><p><br data-mce-bogus="1"></p><p>======= source.mac =======<br></p><p><br data-mce-bogus="1"></p><p>/gate/source/addSource mybeam gps<br>/gate/source/mybeam/gps/particle gamma<br>/gate/source/mybeam/gps/pos/type Beam<br>/gate/source/mybeam/gps/ene/mono 170 keV<br>/gate/source/mybeam/gps/ene/type Gauss<br>/gate/source/mybeam/gps/ene/sigma 1.0 keV<br>/gate/source/mybeam/gps/direction 0 0 -1<br><br>/gate/source/mybeam/gps/position 0 0 0.2 cm<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 mm<br>/gate/source/mybeam/gps/pos/radius 500 um<br>/gate/source/mybeam/gps/pos/halfz 0.01 cm<br>/gate/source/mybeam/gps/ang/type beam2d</p><p><br data-mce-bogus="1"></p></blockquote><p>Thank you for your help,</p><p>Sarah Blind<br> <br><br><br><br data-mce-bogus="1"></p></div></div></body></html>