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Energy Loss

Energy Loss. Graduate School of Scienc e, Tohoku University Toshi Gogami 22/May/2013. GEANT4 Simulation. Energy Loss 12 C 100mg/cm 2 208 Pb 100mg/cm 2 Angular distributions. Setup (1). Simulation code : POSI. Virtual Detector. Target. e. Generate 4500 M eV/c electrons

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Energy Loss

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  1. Energy Loss Graduate School of Science, Tohoku University Toshi Gogami 22/May/2013

  2. GEANT4 Simulation Energy Loss • 12C 100mg/cm2 • 208Pb 100mg/cm2 Angular distributions

  3. Setup (1) Simulation code : POSI Virtual Detector Target e Generate 4500 MeV/c electrons at the center of target ( 200,000 events ) Setup(1)

  4. Simple estimations • 12C 100 mg/cm2 target , X0 = 42700 mg/cm2 ΔE = ( 1.0 – exp(-x/X0) ) * 4500 = 5.3 MeV • 208Pb 100 mg/cm2 target , X0 = 6370 mg/cm2 ΔE = ( 1.0 – exp(-x/X0) ) * 2344 = 35.2 MeV NOTE: Effective thickness 100.0 / 2.0 [ mg/cm2 ] Setup(1)

  5. Simulation Results (12C) Energy Loss Mean : 5.5 MeV (Estimation:5.3MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.023 Most probable energy loss ~ 70 keV Setup(1)

  6. Simulation Results (208Pb) Energy Loss Mean : 37.0 MeV (Estimation:35.2MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.093 Most probable energy loss ~ 50 keV Setup(1)

  7. Setup (2) Simulation code : POSI Virtual Detector Target e Generate 4500 MeV/c electrons at moving generation point within the target Randomly moved ( 200,000 events ) Setup(2)

  8. Simulation Results (12C) Energy Loss Mean : 5.6 MeV (Setup(1) : 5.5MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.024 Setup(2)

  9. Simulation Results (208Pb) Energy Loss Mean : 36.6 MeV (Setup(1):37.0MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.092 Setup(2)

  10. Angular distributions of electrons

  11. Setup (3) Virtual Detector Target Generate 2344 MeV/c electrons at the center of target e Simulation code : POSI (Default HKS setting) 17 degrees Setup(3)

  12. Theta distributions for 12C target MEAN : 0.1 mrad MEAN : 0.2 mrad Setup(3) Setup(1) Setup (1) Incident electrons with 4500 MeV Setup (3) Incident electrons with 2344 MeV

  13. Theta distributions for 208Pb target MEAN : 0.3 mrad MEAN : 0.6 mrad Setup(3) Setup(1) Setup (1) Incident electrons with 4500 MeV Setup (3) Incident electrons with 2344 MeV

  14. Theta distributions for 12C target Moving Generation point MEAN : 0.1 mrad MEAN : 0.1 mrad Setup(2) Setup(1) Setup (1) Incident electrons with 4500 MeV Setup (2) Incident electrons with 4500 MeV

  15. Theta distributions for 208Pb target Moving Generation point MEAN : 0.3 mrad MEAN : 0.3 mrad Setup(2) Setup(1) Setup (1) Incident electrons with 4500 MeV Setup (2) Incident electrons with 4500 MeV

  16. Summary • Energy losses for 12C and 208Pb (Ee = 4500 MeV) • There are long tails which increase the mean values of energy loss largely. • Angular distributions of ( scattered ) electrons • More forward distributions for Ee=4500 MeV than that for Ee=2344 MeV • No big difference between the Setup(1) and Setup(2) for the estimations of angular distributions The difference between setup(1) and setup(2) is just only the behaviors of generation points.

  17. Backup

  18. Setup (4) Virtual Detector Target Generate 2344 MeV/c electrons at moving generation point within the target e Randomly moved ( 200,000 events ) Simulation code : POSI (Default HKS setting) 17degrees Setup(4)

  19. Simulation Results (52Cr 154mg/cm2) Energy Loss Mean : 13.3 MeV (Estimation : 11.9MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.074 Most probable energy loss ~ 85keV Setup(3)

  20. Simulation Results (52Cr 154mg/cm2) Energy Loss Mean : 13.2 MeV (Setup(3) : 13.3MeV) N(<0.5 MeV) : N(>0.5 MeV) = 1 : 0.075 Setup(4)

  21. energyloss.cc //----- Histogram Options ------- //histopt(h1);histopt(h2); // ========== Draw Histograms ==============TCanvas* c1 = new TCanvas("c1","c1"); c1->Divide(1,2); c1->cd(1);gPad->SetGridx();gPad->SetGridy();gPad->SetLogy(1); h1->Draw(); c1->cd(2);gPad->SetGridx();gPad->SetGridy();gPad->SetLogy(1); h2->Draw(); // ===== Number of events ================ double n1,n2; double ratio12; n1 = h1->Integral(0,100); // total n2 = h2->Integral(0,100); // < 5 MeVcout << n1 << " " << n2 << endl; n1 = n1 - n2; // > 5 MeV ratio12 = n1/n2;cout << " 1 : " << ratio12 << endl; // ======== Print ======================= //c1->Print("Pb208_100mg_4.5_center_energyloss.eps","eps"); //c1->Print("Pb208_100mg_4.5_center_energyloss.png","png"); c1->Print("C12_100mg_4.5_center_energyloss.eps","eps"); c1->Print("C12_100mg_4.5_center_energyloss.png","png");} /* energyloss.ccToshi Gogami , 22/May/2013*/void histopt(TH1F*h){ h->GetXaxis()->SetTitle(" [ MeV ] "); h->GetYaxis()->SetTitle(" Counts "); h->SetFillStyle(3005); h->SetFillColor(9); h->GetXaxis()->SetLabelSize(0.05); h->GetXaxis()->SetTitleSize(0.05); h->GetYaxis()->SetLabelSize(0.05); h->GetYaxis()->SetTitleSize(0.05);}void energyloss(char* file){ // ========== General Conditions ==============gROOT->SetStyle("Plain"); //gStyle->SetOptStat(0); // ========== Open ROOT File ===============TFile* f = new TFile(file);TTree* t = (TTree*)f->Get("tree"); // ========== Cut Conditions ===============TCut cut = "eleflag && !eIoni"; // ========== Create Histograms =========== //TH1F*h1 = new TH1F( "h1" , "" , 100 , 0.0 , 2400.0 ); TH1F*h1 = new TH1F( "h1" , "" , 100 , 0.0 , 4600.0 ); TH1F*h2 = new TH1F( "h2" , "" , 100 , 0.0 , 0.5 ); t->Project("h1", "sqrt(pBeam*pBeam+0.511+0.511)-sqrt(pVD*pVD+0.511*0.511)", cut); t->Project("h2", "sqrt(pBeam*pBeam+0.511+0.511)-sqrt(pVD*pVD+0.511*0.511)", cut);

  22. angle.cc /* angle.ccToshi Gogami , 22/May/2013*/void histopt(TH1F*h){ h->GetXaxis()->SetTitle(" [ mrad ] "); h->GetYaxis()->SetTitle(" Counts "); h->SetFillStyle(3005); h->SetFillColor(9); h->GetXaxis()->SetLabelSize(0.05); h->GetXaxis()->SetTitleSize(0.05); h->GetYaxis()->SetLabelSize(0.05); h->GetYaxis()->SetTitleSize(0.05);}void angle(char* file){ // ========== General Conditions ==============gROOT->SetStyle("Plain"); //gStyle->SetOptStat(0); // ========== Open ROOT File ===============TFile* f = new TFile(file);TTree* t = (TTree*)f->Get("tree"); // ========== Cut Conditions ===============TCut cut = "eleflag && !eIoni && theta<0.03"; // ========== Create Histograms =========== //TH1F* h = new TH1F( "h" , "" , 100 , 0.0 , 10.0 ); TH1F* h = new TH1F( "h" , "" , 100 , 0.0 , 30.0 ); t->Project("h","theta*1.0e3",cut);histopt(h); // ========== Draw Histograms ===========TCanvas*c1 = new TCanvas("c1","c1");gPad->SetLogy(1);gPad->SetGridx();gPad->SetGridy(); h->Draw(); }

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