<div dir="ltr"><div>Hello,</div><div><br></div><div>I want to measure the energy spectrum of my source as seen by my SPECT detector (after the energy blurring has been applied by the digitizer). I tried using the EnergySpectrumActor, as described below, but the peak appeared narrower than I expected. I tried changing the energy resolution value in my digitizer (also described below) but changing the value made no difference to the shape of the energy spectrum. <br></div><div>How do I measure the energy spectrum after the blurring is applied - am I using the wrong actor? <br></div><div><br></div><div>#Energy Spectrum Actor<br></div><div></div><div>/gate/actor/addActor   EnergySpectrumActor          Energy<br>/gate/actor/Energy/save                             output/EnergyScoring.root<br>/gate/actor/Energy/energySpectrum/setEmin           90 eV<br>/gate/actor/Energy/energySpectrum/setEmax           170 keV<br>/gate/actor/Energy/energySpectrum/setNumberOfBins   80</div><div>/gate/actor/Energy/enableNbPartSpectrum             true<br>/gate/actor/Energy/attachTo                         crystal_volume</div><div><br></div><div># Energy Blurring in Digitizer<br>/gate/digitizer/Singles/insert blurring<br>/gate/digitizer/Singles/blurring/setLaw inverseSquare<br>/gate/digitizer/Singles/blurring/inverseSquare/setResolution 0.15<br>/gate/digitizer/Singles/blurring/inverseSquare/setEnergyOfReference 140.0 keV</div><div><br></div><div>I am using GATE v9.0 and my source is Tc-99m (140 keV photons).<br></div><div><br></div><div>Many thanks,<br></div><div>Miriam<br></div></div>