Geant4 for GLAST BFEM Comparison with Distributions in BFEM Data –

1. Geant4 for GLAST BFEM • Comparison with Distributions in BFEM Data – • T. Mizuno, H. Mizushima, S. Ogata, Y. Fukazawa (Hiroshima/SLAC) • M. Roterman, P. Valtersson (Royal Inst. of Tech/SLAC) • M. Ozaki (ISAS), • T. Handa, B. Giebels, T. Kamae (SLAC) • (Note) • This work is in progress and hence the report is preliminary. • (Contents) • Hit distributions in BFEM • Two Cosmic Ray Models: with and without 0.6*sin(theta) term in albedo fluxes • Summary

2. Geant4 Simulation for BFEM – A Chart • CR Generator • Primary p, e-, g • Uniform angular distribution • Secondary p, e-,e+,m+,m- • Angular distribution proportional to 1+ 0.6*sin(theta) • Uniform angular distribution (Steve Ritz’s choice) • Secondary g • Angular distribution adjusted to Schoenfelder et al. • Physics Simulation (The fixes not implemented yet) • Digitization (w/charge sharing, w/o noise) • Conversion to IRF File • ROOTWriter (Thanks to Heather) • Analysis (Presented here) • Reconstruction (Yet to be done)

3. Magnetic Rigidity etc for Palestine TX

4. Downward Proton Flux for Palestine TX

5. Downward Electron Flux for Palestine TX

6. Downward and Upward Electron Fluxes

7. Upward Electron Flux for Palestine TX

8. Angular Distributions for Electrons

9. Upward Gamma Ray Flux

10. Angular Distribution for Gamma Rays

11. BFEM L1T Rate (G4 vs Real) for the Level Flight Sharper earth rim with sin(theta) albedo component Total G4 L1T: 517 Hz. (Real data: ~500 Hz) contribution proton: 219 Hz e-: 77.9 Hz e+: 46.2 Hz gamma: 89.0 Hz mu-: 32.8 Hz mu+: 52.7 Hz Neutral: 54.8 Hz. (real data: ~50 Hz) contribution proton: 5.14 Hz e-: 8.09 Hz e+: 4.68 Hz gamma: 34.4 Hz mu-: 1.09 Hz mu+: 1.42 Hz

12. Hits in each layer (G4 vs Real) for “charged” particles Sharper earth rim with sin(theta) albedo component Data G4

13. Hits in each layer (G4) for all “charged” particle species Sharper earth rim with sin(theta) albedo component

14. Tot no. of layers hit (G4 vs Real) for “charged” particles Sharper earth rim with sin(theta) albedo component G4 Data

15. Top-most layer hit (G4 vs Real) for “charged” particles Sharper earth rim with sin(theta) albedo component Data G4

16. Hits in each layer (G4 vs Real) for “neutral” particles Sharper earth rim with sin(theta) albedo component G4 Data

17. Hits in each layer (G4) for all “neutral” particle species Sharper earth rim with sin(theta) albedo component

18. Tot no. of layers hit (G4 vs Real) for “neutral” particles Sharper earth rim with sin(theta) albedo component G4 Data

19. Top-most layer hit (G4 vs Real) for “neutral” particles Sharper earth rim with sin(theta) albedo component Data G4

20. Study on CR protons and muons Sharper earth rim with sin(theta) albedo component • We primarily want to find protons and muons. As these particles normally have • straight tracks we can apply the following cuts: • Chi square of < 0.01 • Hit in ACD panels • Single tracks only • Number of hits in tracker layers • As we have missing silicon in top part of tracker we only look at bottom 16 layers. • The above cuts does not include interactions as they produce several recon tracks.

21. Study on CR protons and muons: Top ACD and 8 layers Sharper earth rim with sin(theta) albedo component MC Protons = Red MC Muons (- & +) = Yellow BFEM data = blue

22. Study on CR protons and muons: All ACD and 8 layers Sharper earth rim with sin(theta) albedo component MC Protons = Red MC Muons (- & +) = Yellow BFEM data = blue

23. Study on CR protons and muons: All ACD and 4 layers Sharper earth rim with sin(theta) albedo component MC Protons = Red MC Muons (- & +) = Yellow BFEM data = blue

24. Study on CR protons and muons: All side ACD and 4 layers Sharper earth rim with sin(theta) albedo component MC Protons = Red MC Muons (- & +) = Yellow BFEM data = blue

25. BFEM L1T Rate (G4 vs Real) for the Level Flight Sharper earth rim without sin(theta) albedo component Total L1T: 448 Hz. (real data: ~500 Hz) contribution proton: 210 Hz e-: 53.7 Hz e+: 32.2 Hz gamma: 89.0 Hz mu-: 22.7 Hz mu+: 40.7 Hz Neutral: 50.1 Hz. (real data: ~50 Hz) contribution proton: 4.55 Hz e-: 5.24 Hz e+: 3.46 Hz gamma: 34.4 Hz mu-: 0.609 Hz mu+: 1.85 Hz

26. Hits in each layer (G4 vs Real) for “charged” particles Sharper earth rim without sin(theta) albedo component Data G4

27. Hits in each layer (G4) for all “charged” particle species Sharper earth rim without sin(theta) albedo component

28. Tot no. of layers hit (G4 vs Real) for “charged” particles Sharper earth rim without sin(theta) albedo component Data G4

29. Top-most layer hit (G4 vs Real) for “charged” particles Sharper earth rim without sin(theta) albedo component Data G4

30. Hits in each layer (G4 vs Real) for “neutral” particles Sharper earth rim without sin(theta) albedo component Data G4

31. Hits in each layer (G4) for all “neutral” particle species Sharper earth rim without sin(theta) albedo component

32. Tot no. of layers hit (G4 vs Real) for “neutral” particles Sharper earth rim without sin(theta) albedo component G4 Data

33. Top-most layer hit (G4 vs Real) for “neutral” particles Sharper earth rim without sin(theta) albedo component Data G4

34. Conclusion: Geant4 for BFEM • Comparison with Distributions in BFEM Data – • (Note) • This work is in progress and hence the report is preliminary. • (Conclusion) • Hit distributions are a powerful way to study the CR composition and angular distribution. • More soft electrons/positrons(E< 20MeV?) to fill the lower portion of the Tracker. • Sharpness of the Earth Rim (as a source of soft gamma rays): BFEM may give a useful measurement! • Strength of the sin(theta) component: BFEM may give a constraint!.