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

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

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

4. Simple estimations 12 C 100 mg/cm 2 target, X 0 = 42700 mg/cm 2 ΔE = ( 1.0 – exp(-x/X 0 ) ) * 4500 = 5.3 MeV 208 Pb 100 mg/cm 2 target, X 0 = 6370 mg/cm 2 ΔE = ( 1.0 – exp(-x/X 0 ) ) * 2344 = 35.2 MeV NOTE: Effective thickness 100.0 / 2.0 [ mg/cm 2 ]

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

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

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

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

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

10. Angular distributions of electrons

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

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

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

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

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

16. Summary Energy losses for 12 C and 208 Pb (E e = 4500 MeV) – There are long tails which increase the mean values of energy loss largely. Angular distributions of ( scattered ) electrons – More forward distributions for E e =4500 MeV than that for E e =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) Simulation code : POSI (Default HKS setting) Generate 2344 MeV/c electrons at moving generation point within the target Target Virtual Detector 17 degrees e ( 200,000 events ) Randomly moved

19. Simulation Results ( 52 Cr 154mg/cm 2 ) Mean : 13.3 MeV (Estimation : 11.9MeV) Energy Loss N( 0.5 MeV) = 1 : 0.074 Most probable energy loss ～ 85 keV

20. Simulation Results ( 52 Cr 154mg/cm 2 ) Mean : 13.2 MeV (Setup(3) : 13.3MeV) Energy Loss N( 0.5 MeV) = 1 : 0.075

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 MeV ratio12 = n1/n2; cout 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.cc Toshi 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.cc Toshi 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 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(); }