<div dir="ltr">Thank you Alessandro for your quick reply. I created the sector following step by step the manual and I didn't miss any step of the hierarchy(I think so). I attach the code for my geometry construction. #===================================================== # CYLINDRICAL SYSTEM #===================================================== /gate/world/daughters/name cylindricalPET /gate/world/daughters/insert cylinder /gate/cylindricalPET/placement/setTranslation 0.0 0.0 0.0 cm /gate/cylindricalPET/geometry/setRmax 73. mm /gate/cylindricalPET/geometry/setRmin 63. mm /gate/cylindricalPET/geometry/setHeight 100. mm /gate/cylindricalPET/setMaterial Air /gate/cylindricalPET/vis/forceWireframe /gate/cylindricalPET/vis/setColor white /vis/viewer/zoom 1 #===================================================== # HEAD-Rsector #===================================================== /gate/cylindricalPET/daughters/name rsector /gate/cylindricalPET/daughters/insert box /gate/rsector/placement/setTranslation 71. 0. -25.64 mm /gate/rsector/geometry/setXLength 10. mm /gate/rsector/geometry/setYLength 46.03 mm /gate/rsector/geometry/setZLength 46.03 mm /gate/rsector/setMaterial Air /gate/rsector/vis/forceWireframe /gate/rsector/vis/setColor red #===================================================== # HEAD1-Rsector #===================================================== /gate/cylindricalPET/daughters/name rsector1 /gate/cylindricalPET/daughters/insert box /gate/rsector1/placement/setTranslation 71. 0. 25.5 mm /gate/rsector1/geometry/setXLength 10. mm /gate/rsector1/geometry/setYLength 46.03 mm /gate/rsector1/geometry/setZLength 46.03 mm /gate/rsector1/setMaterial Air /gate/rsector1/vis/forceWireframe /gate/rsector1/vis/setColor red #===================================================== # MODULE #===================================================== /gate/rsector/daughters/name module /gate/rsector/daughters/insert box /gate/module/geometry/setXLength 10. mm /gate/module/geometry/setYLength 46.03 mm /gate/module/geometry/setZLength 46.03 mm /gate/module/setMaterial Air /gate/module/vis/forceWireframe /gate/module/vis/setColor yellow #===================================================== # MODULE1 #===================================================== /gate/rsector1/daughters/name module1 /gate/rsector1/daughters/insert box /gate/module1/geometry/setXLength 10. mm /gate/module1/geometry/setYLength 46.03 mm /gate/module1/geometry/setZLength 46.03 mm /gate/module1/setMaterial Air /gate/module1/vis/forceWireframe /gate/module1/vis/setColor yellow #===================================================== # CRYSTAL #===================================================== /gate/module/daughters/name crystal /gate/module/daughters/insert box /gate/crystal/geometry/setXLength 10. mm /gate/crystal/geometry/setYLength 1.51 mm /gate/crystal/geometry/setZLength 1.51 mm /gate/crystal/setMaterial Air /gate/crystal/vis/forceWireframe /gate/crystal/vis/setColor magenta #===================================================== # CRYSTAL1 #===================================================== /gate/module1/daughters/name crystal1 /gate/module1/daughters/insert box /gate/crystal1/geometry/setXLength 10. mm /gate/crystal1/geometry/setYLength 1.51 mm /gate/crystal1/geometry/setZLength 1.51 mm /gate/crystal1/setMaterial Air /gate/crystal1/vis/forceWireframe /gate/crystal1/vis/setColor yellow #===================================================== # LAYER #===================================================== /gate/crystal/daughters/name LYSO /gate/crystal/daughters/insert box /gate/LYSO/geometry/setXLength 10. mm /gate/LYSO/geometry/setYLength 1.51 mm /gate/LYSO/geometry/setZLength 1.51 mm /gate/LYSO/setMaterial LYSO /gate/LYSO/vis/setColor green #===================================================== # LAYER1 #===================================================== /gate/crystal1/daughters/name LYSO1 /gate/crystal1/daughters/insert box /gate/LYSO1/geometry/setXLength 10. mm /gate/LYSO1/geometry/setYLength 1.51 mm /gate/LYSO1/geometry/setZLength 1.51 mm /gate/LYSO1/setMaterial LYSO /gate/LYSO1/vis/setColor magenta #===================================================== # PSPMT #===================================================== /gate/module/daughters/name PMT /gate/module/daughters/insert box /gate/PMT/placement/setTranslation 10. 0. 0. mm /gate/PMT/geometry/setXLength 10. mm /gate/PMT/geometry/setYLength 49. mm /gate/PMT/geometry/setZLength 49. mm /gate/PMT/vis/forceSolid #/gate/PMT/setMaterial /gate/PMT/vis/setColor yellow #===================================================== # PSPMT1 #===================================================== /gate/module1/daughters/name PMT1 /gate/module1/daughters/insert box /gate/PMT1/placement/setTranslation 10. 0. 0. mm /gate/PMT1/geometry/setXLength 10. mm /gate/PMT1/geometry/setYLength 49. mm /gate/PMT1/geometry/setZLength 49. mm /gate/PMT1/vis/forceSolid #/gate/PMT1/setMaterial /gate/PMT1/vis/setColor yellow #===================================================== # REPEAT CRYSTAL #===================================================== /gate/crystal/repeaters/insert cubicArray /gate/crystal/cubicArray/setRepeatNumberX 1 /gate/crystal/cubicArray/setRepeatNumberY 29 /gate/crystal/cubicArray/setRepeatNumberZ 29 /gate/crystal/cubicArray/setRepeatVector 0. 1.6 1.6 mm #===================================================== # REPEAT CRYSTAL1 #===================================================== /gate/crystal1/repeaters/insert cubicArray /gate/crystal1/cubicArray/setRepeatNumberX 1 /gate/crystal1/cubicArray/setRepeatNumberY 29 /gate/crystal1/cubicArray/setRepeatNumberZ 29 /gate/crystal1/cubicArray/setRepeatVector 0. 1.6 1.6 mm #===================================================== # REPEAT PMT TUBE #===================================================== /gate/PMT/repeaters/insert cubicArray /gate/PMT/cubicArray/setRepeatNumberX 1 /gate/PMT/cubicArray/setRepeatNumberY 1 /gate/PMT/cubicArray/setRepeatNumberZ 1 /gate/PMT/cubicArray/setRepeatVector 0. 1.6 1.6 mm #===================================================== # REPEAT PMT1 TUBE #===================================================== /gate/PMT1/repeaters/insert cubicArray /gate/PMT1/cubicArray/setRepeatNumberX 1 /gate/PMT1/cubicArray/setRepeatNumberY 1 /gate/PMT1/cubicArray/setRepeatNumberZ 1 /gate/PMT1/cubicArray/setRepeatVector 0. 1.6 1.6 mm #===================================================== # REPEAT MODULE #===================================================== /gate/module/repeaters/insert cubicArray /gate/module/cubicArray/setRepeatNumberZ 1 /gate/module/cubicArray/setRepeatVector 0. 0. 46.1 mm #===================================================== # REPEAT MODULE1 #===================================================== /gate/module1/repeaters/insert cubicArray /gate/module1/cubicArray/setRepeatNumberZ 1 /gate/module1/cubicArray/setRepeatVector 0. 0. 46.1 mm #===================================================== # REPEAT RSECTOR #===================================================== /gate/rsector/repeaters/insert linear /gate/rsector/linear/setRepeatNumber 1 /gate/rsector/linear/setRepeatVector 0. 0. 46.3 mm /gate/rsector/repeaters/insert ring /gate/rsector/ring/enableAutoRotation /gate/rsector/ring/setFirstAngle 0 deg /gate/rsector/ring/setRepeatNumber 8 /gate/rsector1/repeaters/insert linear /gate/rsector1/linear/setRepeatNumber 1 /gate/rsector1/linear/setRepeatVector 0. 0. 46.3 mm /gate/rsector1/repeaters/insert ring /gate/rsector1/ring/enableAutoRotation /gate/rsector1/ring/setFirstAngle 0 deg /gate/rsector1/ring/setRepeatNumber 8 #===================================================== # ATTACH SYSTEM #===================================================== /gate/systems/cylindricalPET/rsector/attach rsector /gate/systems/cylindricalPET/rsector/attach rsector1 /gate/systems/cylindricalPET/module/attach module /gate/systems/cylindricalPET/module/attach module1 /gate/systems/cylindricalPET/crystal/attach crystal /gate/systems/cylindricalPET/crystal/attach crystal1 /gate/systems/cylindricalPET/layer1/attach LYSO /gate/systems/cylindricalPET/layer1/attach LYSO1 #===================================================== # DEFINITION OF YOUR PHANTOM #===================================================== /gate/world/daughters/name phantom /gate/world/daughters/insert cylinder /gate/phantom/geometry/setRmin 0. mm /gate/phantom/geometry/setRmax 20. mm /gate/phantom/geometry/setHeight 20. mm /gate/phantom/placement/setTranslation 0. 0. 0. mm /gate/phantom/setMaterial Water /gate/phantom/vis/forceSolid /gate/phantom/vis/setColor blue #===================================================== # ATTACH PHANTOM SD & # ATTACH LAYER SD #===================================================== /gate/phantom/attachPhantomSD /gate/PMT/attachPhantomSD /gate/PMT1/attachPhantomSD /gate/LYSO/attachCrystalSD /gate/LYSO1/attachCrystalSD </div>