XRay Astronomy Satellite Casestudy

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X-Ray Astronomy Satellite Case-study
Stefano, Pedro, John, Simone, Ramon,
Vladimir, Hugh, Petteri, Eamonn

• Objectives
• Demonstrate status of Geant4 in a non-developer
  environment
• Explore shortcomings for space ( other)
  applications
• Apply Geant4 to a real-life problem
• Promote Geant4

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The Current Challenge
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What can cause problems for X-ray CCDs?

• Radiation belt electrons?
• Scattering in the mirror shells?
• Effectiveness of magnetic broom baffle?
• Electron damage mechanism? - NIEL?
• Other particles? Protons, cosmics?
• Path to CCD? wall penetration? anomalous
  magnetic focussing?
• Apply Geant4...

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Focal Plane8 CCDs, 6 Front-illuminated, 2 back
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Magnetic Baffle

• Arrangement of permanent magnets half-way down
  tube.

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Mirror Shells
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Tube, collimator detector housing
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Results

• Demonstrate status of G4 in non-developer
  environment
• mature in terms of capabilities but even
  experienced developers had problems
• took many iterations to define geometry - normal
  in cases of incomplete specifications/ unfamiliar
  applications
• Explore shortcomings for space ( other)
  applications
• low-? mirror scattering - should be ok for e-
• efficiency of isotropic sources
• magnetic field definition not trivial
• Apply Geant4 to a real-life problem
• a very good case and very applicable
• Promote Geant4
• will occur if we continue to a useful result

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Results...

• 107 particles gave 22 events on CCD (no B)
• actual flux on tube 1012 /sec
• so flux at CCD is relatively high
• TBD
• actual flux scaling
• effect of B (relative)
• event characteristics at CCD
• improve efficiency

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Thanks a million to the team