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## Re: number of optical photons remains constant

Forum: Processes Involving Optical Photons
Re: number of optical photons remains constant (Cejo George)
Re: Re: number of optical photons remains constant (Gumplinger Peter)
Date: 02 Apr, 2012
From: Ashwath Rao <Ashwath Rao>

 ```hello everyone, I am Ashwath Rao, working with Cejo George. ``` ```We have taken a dump from G4SteppingVerbose.cc, for SUM of energies within a range of 1300 (assuming op. photon energies lie within 1300 eV). Its a Trial only and have included following code : //====================================================================== G4double sum=0; for(size_t lp1=(*fSecondary).size()-tN2ndariesTot; lp1<(*fSecondary).size(); lp1++) { if (((*fSecondary)[lp1]->GetKineticEnergy()*1000000)<1300) { sum = sum + ((*fSecondary)[lp1]->GetKineticEnergy()*1000000); } G4cout << G4BestUnit((*fSecondary)[lp1]->GetKineticEnergy() , "Energy") << G4endl; } //&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& FILE *pFile12; pFile12=fopen("N08SVG4Run12.csv","a+"); if (pFile12!=NULL) { if(sum>0) { fprintf(pFile12,"%f\n",sum); } } fclose(pFile12); sum=sum*0; //======================================================================``` 1) We feel that each gamma after the interaction can be identified by the sum of the optical photon energies rather than plotting the individual op. photon energies !! (ARE WE RIGHT SIR..?) 2) What is the range of op. photon energy values? below 1300 eV.? 3) We are getting a histogram as attached. (A) SUM - histogram (B) op.photon energies histogram for 10,000 run beam events with 662 keV gamma. Thank you Sir for your valuable time. Regards, Ashwath. ``` Attachment: http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2012/04/02/13.11-31922-SUM.jpg http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2012/04/02/13.11-70675-OpPhEnergies.pngOn Mon, 02 Apr 2012 16:58:20 GMT, Gumplinger Peter wrote: > Hi Cejo, > > I don't know what the error could be. You are correct, in general, you'd > expect to see, on average, half/double the number of optical photons > from G4Scintillation for half/double the deposited energy. > > I don't know how you tally the number of optical photons generated (I > presume, in StackingAction) but can you also histogram the deposited > total energy in your NaI volume. Apart from Birks Correction (saturation > effect) the number of scintillation photons is proportional to the > deposited total energy by the Scintillation Yield you specified. > > Peter > ```

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1 Re: number of optical photons remains constant   (Gumplinger Peter - 02 Apr, 2012)
Re: number of optical photons remains constant   (Cejo George - 03 Apr, 2012)
Re: number of optical photons remains constant   (Gumplinger Peter - 03 Apr, 2012)
Re: number of optical photons remains constant   (Ashwath Rao - 05 Apr, 2012)
Re: number of optical photons remains constant   (Ashwath Rao - 06 Apr, 2012)
 to: "Re: number of optical photons remains constant"
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