<div dir="ltr">Dear all,<div><br></div><div>I am doing a sensitivity evaluation test of Biograph Vision, but the result showed an unignorable sensitivity outside the axial FOV, around 2% away from the axial edge, which means that there are still some coincidences detected. </div><div><br></div><div>The following is my digitizer and source setting:</div><div>```</div><div>/gate/physics/Gamma/SetCutInRegion      LYSO .5 mm<br>/gate/physics/Electron/SetCutInRegion   LYSO .50 mm<br>/gate/physics/Positron/SetCutInRegion   LYSO .50 mm<br><br>#=====================================================<br>#   D I G I T I Z E R<br>#====================================================<br>#       A D D E R<br>/gate/digitizer/Singles/insert adderCompton<br>/gate/digitizer/Singles/insert adder<br><br>#       R E A D O U T<br>/gate/digitizer/Singles/insert readout<br>/gate/digitizer/Singles/readout/setDepth  4  <br>#/gate/digitizer/Singles/insert timeResolution<br>#/gate/digitizer/Singles/timeResolution/setTimeResolution 0.3 ns<br><br><br>#      E N E R G Y   B L U R R I N G <br>/gate/digitizer/Singles/insert blurring<br>/gate/digitizer/Singles/blurring/setResolution 0.15<br>/gate/digitizer/Singles/blurring/setEnergyOfReference 511. keV<br><br>#       E N E R G Y   C U T <br>/gate/digitizer/Singles/insert thresholder<br>/gate/digitizer/Singles/thresholder/setThreshold 450. keV<br>/gate/digitizer/Singles/insert upholder<br>/gate/digitizer/Singles/upholder/setUphold 650. keV<br><br>#       D E A D    T I M E <br>/gate/digitizer/Singles/insert deadtime<br>/gate/digitizer/Singles/deadtime/setDeadTime 320 ns<br>/gate/digitizer/Singles/deadtime/setMode paralysable<br>/gate/digitizer/Singles/deadtime/chooseDTVolume crystal<br><br>#       C O I N C I    S O R T E R<br>/gate/digitizer/Coincidences/setInputName Singles<br>/gate/digitizer/Coincidences/setWindow 4.7 ns<br>/gate/digitizer/Coincidences/setOffset 0. ns<br>#/gate/digitizer/Coincidences/setDepth 4<br>/gate/digitizer/Coincidences/MultiplesPolicy takeWinnerIfIsGood<br></div><div><br></div><div>===============================</div><div><br># SOURCE<br>/gate/source/addSource F18SphereSource<br>/gate/source/F18SphereSource/setActivity 100000. becquerel<br>/gate/source/F18SphereSource/gps/particle e+<br>/gate/source/F18SphereSource/setForcedUnstableFlag true<br>/gate/source/F18SphereSource/setForcedHalfLife 6586 s<br>/gate/source/F18SphereSource/setType backtoback<br>#/gate/source/F18SphereSource/setAccolinearityFlag      true<br>#/gate/source/F18SphereSource/setAccoValue 2 deg<br>/gate/source/F18SphereSource/gps/energytype Fluor18<br>#/gate/source/F18SphereSource/gps/monoenergy 511. keV<br><br><br>/gate/source/F18SphereSource/gps/type Surface<br>/gate/source/F18SphereSource/gps/shape Sphere<br>/gate/source/F18SphereSource/gps/radius 0.15 mm<br>/gate/source/F18SphereSource/gps/centre 0.0 0.0 {axialOffset} cm<br># Gurantees particles will shoot in all directions<br>/gate/source/F18SphereSource/gps/angtype iso<br></div><div>```</div><div>I don't apply noise for now, so I am guessing there might be something wrong with the digitizer. But I am not sure because I didn't see any obvious result change no matter how I optimize it. Does anyone have any idea about that? Any answer will be highly appreciated! Thanks!</div><div><br></div><div>Best,</div><div></div></div>