GenIma: program to simulate emulsions

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GenIma program to simulate emulsions
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• Reconstruction optimization and parameters
  understanding are difficult for emulsions
• Lack of data for various conditions ( particle
  type, angles, energies, fog densities, ambiant
  radioactivity integration times, etc) and poor
  statistics.
• Large feed-back time between beam tests and
  scanning
• ECC efficiency evaluation will be needed

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• GEN Particles generation in GEANT 3.2
• Anything you like as particles, energies,
  dE/dX, vertices, neutrinos events, etc
• Keep the coordinates of energy deposites in a
  volume 200? 200? 288 ?3 2?1 ? dead-zone
• Density of 30 grains/100?
• ?-rays generated
• Track density controlled ( ex 10/field of view)

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The virtual microscope
Focused plane
ccd plane
objective
d3.254 mm
Grain plane
d200 mm
?
r6mm
The systeme objective-ccd (in red) can move along
the optical axis we keep 16 tomographic planes
? is defined by objective characteristics
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• IMA makes pictures fom GEN output
• For each grain x,y,z , intercept the ccd
  surface by a conical prolongation ? surface S of
  pixels to darken. cone aperture N.A
  (numerical aperture)
• ?
  arcsin(N.A/nrefr )
• Fill them with grey in each of the 32 picture
  planes grey density varies with 1 / S and e-d/?
  ( ? is an effective emulsion attenuation
  lenghth)
• Lateral size of grains appropriate smearing
  matrix
• z- grain size 5 z values displaced by (0.6 ?
  /5) (luxuous)
• Linear or parabolic distorsions included (exflat
  from 0 to 40mrad)
• Objective geometrical distorsions, non-uniform
  lighting
• Pictures are written in Fortran (PPM format),
  then converted in JPEG or BMP with XView.

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My objective

• Dry ( oil) objective N.A 0.8 , G ? 50
• Focal length f3.23 mm
• Distance objective-ccd plane 200 mm G62.5
• ccd 1024 ?1024 pixels 12 ?12 ?2
• thin lense approximation, no explicite
  diffraction (? included in matrix)
• sin? N.A/nrefr
• (in a camera objective luminosity
  f/Dobj1/2.tg (?) )
• ? 32o in emulsion

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Format PPM

• http//cedric.cnam.fr/gouet/Var/ppm.html
• Example toto.ppm
• P3
• 4 4
• 255
• red green blue
• 0 0 0 16 16 16 32 32 32 48 48 48
• 64 64 64 80 80 80 96 96 96 112 112 112
• 128 128 128 143 143 143 159 159 159 175 175 175
• 191 191 191 207 207 207 223 23 223 239 239 239

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Fog and background

• Fog is randomly generated as single grain with a
  density of 6 grains/ (10 ?)3
• time consuming, but
• Albums of fogs can be generated only once, and
  pictures added to the tracks ones
• Album of real emulsions data can be used also
  (fogradioactivity fossiles tracks after
  refreshing)
• An ultimate uniform grey layer is added at the
  end (light scattering, long distance shadows)

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Oil and air (without fog) NA0.8 electrons
0.2-1 MeV
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Oil and air (without fog) NA0.8 electrons
0.2-1 MeV
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Emulsion simulation

• 16 images

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Emulsion simulation

• 16 images

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Emulsion simulation

• 16 images

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Emulsion simulation

• 16 images

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Emulsion simulation

• 16 images

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Emulsion simulation

• 16 images

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Depth of field

• From geometry, depth of field can be shorter for
  oil since ? is larger.
• But diffraction is imposing a minimum spot radius
  (Airy distribution)
• NIKON handbook
• dof?.n/NA2n.esep/NA

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2 GeV

• 80 MeV

Oil objective Dry objective
2 ?
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An applicationbase track efficiency

• (extremely preliminary)
• Distorsion (0-40 mrad)
• Clustering just threshold and saturation
• Start from top microtrack, open a 50 mrad cone
• Find n clusters in bottom road n?6?
• Efficiency for base track association 0.93 (0
  mrad)
• Increase with angle
  0.95 (300 mrad)
• Sysal filter or micro track finder responsible
  for this measured fact? Inject Genima pictures
  (or code ) in Sysal
• What is this dependency (if any) with the
  UTS,SUTS tools?
• simulate pulse height

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Next steps

• Release a Fortran version with documentation
  (Sysal)
• Pictures are in FEDRA (Dominique)
• Albums of various background
• Refreshing action parametrization
• Filtering in GenIma to reduce heavy pictures?
• andneutrino events with several emulsions and
  lead ?