<html> <head> </head> <body class='hmmessage'><div dir='ltr'> <style></style> <div dir="ltr">Hi Gate users,<div>I'm doing a thesis where I have to simulate the behavior of an Albira microPET scanner with 2 rings, each having 8 PET detectors placed in octogonal shape: I attach a figure to explain the model and how the detectors are numerated. In the Coincidences output file I found out that GATE doesn't accept coincidences occurred between opposite detectors belonging to the same ring (in the figure, they are the couples 0-8, 2-10, 4-12, 6-14 in the green ring, and 1-9, 3-11, 5-13, 7-15 in the second ring), even though I have fixed the minSectorDifferencer at 1. Can someone explain me why, and how to solve this problem? I attach also the macros describing the structure of the scanner.</div><div><br></div><div>Thank you very much!</div><div>Stefania Cazzato</div><div><br></div><div><br></div><div><div># PETscanner: </div><div><br></div><div>/gate/world/daughters/name PETscanner</div><div><br></div><div>/gate/world/daughters/insert cylinder</div><div><br></div><div>/gate/PETscanner/setMaterial Air</div><div><br></div><div>/gate/PETscanner/geometry/setRmax 70 mm</div><div><br></div><div>/gate/PETscanner/geometry/setRmin 55.8 mm</div><div><br></div><div>/gate/PETscanner/geometry/setHeight 150 mm<span style="font-size: 12pt;"> </span></div><div><span style="font-size: 12pt;"><br></span></div><div>/gate/PETscanner/vis/setColor grey</div><div><br></div><div>/gate/PETscanner/vis/forceWireframe</div><div><br></div><div>/gate/PETscanner/vis/setVisible 1</div><div><br></div><div><br></div><div># PETscanner1 (Cylinder where we put the trpd shape)</div><div><br></div><div>/gate/PETscanner/daughters/name PETscanner1</div><div><br></div><div>/gate/PETscanner/daughters/insert cylinder</div><div><br></div><div>/gate/PETscanner1/setMaterial Air</div><div><br></div><div>/gate/PETscanner1/geometry/setRmax 70 mm</div><div><br></div><div>/gate/PETscanner1/geometry/setRmin 0 mm</div><div><br></div><div>/gate/PETscanner1/geometry/setHeight 150 mm<span style="font-size: 12pt;"> </span></div><div><br></div><div>/gate/PETscanner1/vis/setColor grey</div><div><br></div><div>/gate/PETscanner1/vis/forceWireframe</div><div><br></div><div>/gate/PETscanner1/vis/setVisible 0</div><div><br></div><div>#</div><div>/gate/PETscanner1/placement/setRotationAxis 0 1 0 </div><div><br></div><div>/gate/PETscanner1/placement/setRotationAngle 90 deg</div><div><br></div><div>#</div><div><span style="font-size: 12pt;"># ----------------------------------------------------------</span></div><div># Trapezoid </div><div><br></div><div>/gate/PETscanner1/daughters/name trapezoid </div><div><br></div><div>/gate/PETscanner1/daughters/insert trpd </div><div><br></div><div>/gate/trapezoid/geometry/setX1Length 40 mm </div><div><br></div><div>/gate/trapezoid/geometry/setY1Length 40 mm </div><div><br></div><div>/gate/trapezoid/geometry/setX2Length 50 mm </div><div><br></div><div>/gate/trapezoid/geometry/setY2Length 50 mm </div><div><br></div><div>/gate/trapezoid/geometry/setZLength 12 mm </div><div><br></div><div>/gate/trapezoid/setMaterial LYSOAlbira </div><div><br></div><div>/gate/trapezoid/vis/setColor green</div><div><br></div><div>/gate/trapezoid/vis/forceWireframe </div><div><br></div><div>/gate/trapezoid/placement/setTranslation 0. 0. 62. mm</div><div><br></div><div>/gate/trapezoid/vis/setVisible 1</div><div><br></div><div>#</div><div><br></div><div>#trapezoid is repeated around x axis </div><div><br></div><div><span style="font-size: 12pt;">/gate/trapezoid/repeaters/insert ring </span></div><div><br></div><div>/gate/trapezoid/ring/enableAutoRotation </div><div><br></div><div>/gate/trapezoid/ring/setFirstAngle 270 deg</div><div><br></div><div># the above line sets the first detector at 12 hour </div><div><br></div><div>/gate/trapezoid/ring/setPoint1 0. 0. 0. mm </div><div><br></div><div>/gate/trapezoid/ring/setPoint2 1. 0. 0. mm </div><div><br></div><div>/gate/trapezoid/ring/setRepeatNumber 8 </div><div><br></div><div>/gate/trapezoid/repeaters/insert cubicArray </div><div><br></div><div>/gate/trapezoid/cubicArray/setRepeatNumberX 2 </div><div><br></div><div>/gate/trapezoid/cubicArray/setRepeatVector 54.4 0.0 0.0 mm </div><div><br></div><div>#</div><div># ----------------------------------------------------------</div><div># FrontPad </div><div>#</div><div><br></div><div>/gate/world/daughters/name FrontPad </div><div><br></div><div>/gate/world/daughters/insert box </div><div><br></div><div>/gate/FrontPad/geometry/setXLength 1.9 mm </div><div><br></div><div>/gate/FrontPad/geometry/setYLength 40. mm </div><div><br></div><div>/gate/FrontPad/geometry/setZLength 40. mm </div><div><br></div><div>/gate/FrontPad/placement/setTranslation 54.85 0. 0. mm </div><div><br></div><div>/gate/FrontPad/setMaterial Nylon </div><div><br></div><div>/gate/FrontPad/vis/setColor blue </div><div><br></div><div>/gate/FrontPad/vis/forceWireframe </div><div><br></div><div>/gate/FrontPad/vis/setVisible 1</div><div><br></div><div>##</div><div><br></div><div>/gate/FrontPad/repeaters/insert cubicArray </div><div><br></div><div>/gate/FrontPad/cubicArray/setRepeatNumberZ 2</div><div><br></div><div>/gate/FrontPad/cubicArray/setRepeatVector 0.0 0.0 54.4 mm </div><div><br></div><div>/gate/FrontPad/repeaters/insert ring </div><div><br></div><div>/gate/FrontPad/ring/enableAutoRotation </div><div><br></div><div>/gate/FrontPad/ring/setRepeatNumber 8</div><div><br></div><div>#</div><div># ----------------------------------------------------------</div><div><br></div><div># ATTACH SYSTEM : definition of your global detector </div><div><br></div><div>/gate/systems/PETscanner/level1/attach trapezoid</div><div><br></div><div># ATTACH LAYER SD :</div><div><br></div><div>/gate/trapezoid/attachCrystalSD</div><div><br></div><div><br></div></div></div> </div></body> </html>