Geant4 for GLAST BFEM

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
  0.6sin(theta) term in albedo fluxes
• Summary

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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
  0.6sin(theta)
• Uniform angular distribution (Steve Ritzs
  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)

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Magnetic Rigidity etc for Palestine TX
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Downward Proton Flux for Palestine TX
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Downward Electron Flux for Palestine TX
6
Downward and Upward Electron Fluxes
7
Upward Electron Flux for Palestine TX
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Angular Distributions for Electrons
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Upward Gamma Ray Flux
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Angular Distribution for Gamma Rays
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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
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Hits in each layer (G4 vs Real) for charged
particles Sharper earth rim with sin(theta)
albedo component
Data
G4
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Hits in each layer (G4) for all charged
particle species Sharper earth rim with
sin(theta) albedo component
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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
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Hits in each layer (G4 vs Real) for neutral
particles Sharper earth rim with sin(theta)
albedo component
G4
Data
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Hits in each layer (G4) for all neutral
particle species Sharper earth rim with
sin(theta) albedo component
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Tot no. of layers hit (G4 vs Real) for neutral
particles Sharper earth rim with sin(theta)
albedo component
G4
Data
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Top-most layer hit (G4 vs Real) for neutral
particles Sharper earth rim with sin(theta)
albedo component
Data
G4
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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 lt 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.

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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
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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
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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
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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
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Hits in each layer (G4 vs Real) for charged
particles Sharper earth rim without sin(theta)
albedo component
Data
G4
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Hits in each layer (G4) for all charged
particle species Sharper earth rim without
sin(theta) albedo component
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Tot no. of layers hit (G4 vs Real) for charged
particles Sharper earth rim without sin(theta)
albedo component
Data
G4
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Top-most layer hit (G4 vs Real) for charged
particles Sharper earth rim without sin(theta)
albedo component
Data
G4
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Hits in each layer (G4 vs Real) for neutral
particles Sharper earth rim without sin(theta)
albedo component
Data
G4
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Hits in each layer (G4) for all neutral
particle species Sharper earth rim without
sin(theta) albedo component
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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
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• 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(Elt 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!.