HRRL Pos Test 27Jul2012 Data Ana 3 MeV

3 MeV

2 ways to calculate electron charge

    NE(Int_t ri, Int_t Reprate, Int_t calc_meth){
    printf("%d %d \n",ri, Reprate);
    if(ri==1) TFile *f = new TFile("C:/Users/sadiq/Documents/phd/Runs_Jul_2012/rootfiles/7-27-12/r3735.root");
    else if(ri==2) TFile *f = new TFile("C:/Users/sadiq/Documents/phd/Runs_Jul_2012/rootfiles/7-27-12/r3737.root");
    TTree *ntuple = (TTree*)f->Get("ntuple");
    TH1F *f9=new TH1F("f9","ADC9",4000,0,4000);	 	 
       TCanvas * c2 = new TCanvas("c2", "c2",600 ,500);
       c2->cd();
       Long64_t ne;
       printf("%d \n", ne);
      //method 1 is reprate times single pulse charge

method 1

       Double_t Qp1=0,Qp2=0;
       if(calc_meth == 1){	
       //ntuple->Draw("ADC9*(1.22*1e-9)/50>>f9","1"); 
       ntuple->Draw("ADC9>>f9"); 
       //Qp2 = (f9->Integral())*(1.22*1e-9)/50; //charge calculate with method 2.
       //f9->Fit("gaus");
       ADC9_fit_mean = f9->GetMean(1); 
       //ADC9_fit_mean = ADC9->GetMean(1); 
       printf("ADC9_fit_mean = %d \n",ADC9_fit_mean);
       Qp1 = ADC9_fit_mean*(1.22*1e-9)/50; //Qp: charge per pulse. The calibration: 1.22 (9nV s)/(ADC channel), 50 ohm Terminal.
       printf("QP1=%g\n\n",Qp1);
       printf("e- charge per pulse with method 1: %g\n",Qp1);
       //printf("Reprate: %d\n",Reprate);
       Qs=Reprate*Qp1; //Qs: Charge per second.
       //printf("e- charge per second: %g\n",Qs);
       ne=Qs/Q_e; //Ne: number of electrons per second.
               }

method 2

       if(calc_meth == 2){	 
       //ntuple->Draw("ADC9*(1.22*1e-9)/50>>f9","1"); 
       ntuple->Draw("ADC9>>f9"); 
       printf("%bin# Bin Content%d\n");
       for(i=1; i<=4000; i++){
       //for(i=0; i<=600; i++){
       bin_content[i] = f9->GetBinContent(i);
       //Qp2+=(i*(1.22*1e-9)/50)*bin_content[i];
       Qp2+=i*bin_content[i]*(1.22*1e-9)/50;
       //printf("%d  %d  %g \n",i,bin_content[i],Qp2);
       }

       //printf("Integral = %d \n",f9->Integral());
       //Qp2 = (f9->Integral())*(1.22*1e-9)/50; //charge calculate with method 2.    
       printf("QP2=%g\n\n",Qp2);
       printf("total e- charge in this run with method 2: %g\n",Qp2);
       //printf("Reprate: %d\n",Reprate);
       Qs=Qp2; //Qs: Charge per second.
       printf("e- charge per second: %g\n",Qs);
       printf("e- charge: %g\n",Q_e);	 
       ne=Qs/Q_e; //Ne: number of electrons per second.
       printf("1. total number of electrons in this run: %g\n",ne);
               }		 
       printf("2. total number of electrons in this run: %g\n",ne);
       c2->Close();
       f->Close();
       return(ne);
       }

results in 3 MeV

results on 3 MeV with Method 1

run in	run out	NaI Left	NaI Right	e- rate (Hz)	e+ rate (Hz)	e+/e+ ratop
3735	3736			3.91498e+013	0.25656	6.55329e-015
3737	3736			4.14545e+013	0.251457	6.06586e-015

results on 3 MeV with Method 2

run in	run out	NaI Left	NaI Right	e- rate (Hz)	e+ rate (Hz)	e+/e+ ratop
3735	3736			1.18161e+015	0.25656	2.16258e-013
3737	3736			2.16202e+015	0.251457	1.27239e-013

Hand calculation on electron rate

At full current on Faraday cup 1 we have 1201 nVs/ADC channel.

[math]\frac{1201~nVs}{50 \Omega} = 24~nAs = 24~nC[/math]

charge rate under 300 Reprate: [math]300 \times 24~nAs = 7200~nC = 7.2 \frac{\mu C }{ s}[/math]

[math] \frac{7.2 \times 10^{-6}\frac{ C }{ s}} {1.6 \times 10^{-19} C} = 4.5 \times 10^{13}[/math]

[go back]