Alex Howard, CERN Slide 1

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Simulating Dark Matter Detectors(a.k.a. DMX
Underground Advanced Example)

1. Dark Matter detectors
2. Implementation within Geant4
3. Running DMX advanced example
4. Output AIDA and PI
5. Conclusions

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UKDMC Experiment
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DMX
( Dark Matter eXperiment )
underground physics advanced example
Developed from Last Years Workshop Project
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The DMX advanced example

• The Dark Matter eXample was released with Geant
  4.4.0 and updated with release 4.4.1 (geometry,
  analysis)
• Gives example of Dark Matter type experiment with
  a scintillator target (LXe), low energy physics
  interactions, ray tracing of scintillation of
  photons and time constants introduced to
  demonstrate discrimination

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User Example Class Diagram
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DMX Class Diagram
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(No Transcript)
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Internal Structure
To full construction
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Laboratory Geometry Implementation
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Laboratory Geometry Implementation
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detector
world
detector
detail
source
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Ray Tracing
mirror
GXe
LXe
source
PMT
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hits
Evt Etot LXe LXeTime PMT PmtTime
First Flags MeV hits ns
hits ns hit 0 0.0600 104
0.00057 48 35.98 gamma gamma electron 2
0.0308 121 4.8e-06 37 52.21
gamma gamma electron 3 3.9547 4538
2.7e17 1733 19.55 alpha electron other 4
5.2674 7521 8.1e-05 11356 21.83
alpha electron other 5 0.0860 204
1.3e-3 84 16.93 Xe1290.0 other
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PhysicsList
transportation
user cuts step, time
optical
selective scintillation
electromagnetic
low energy models
neutronHP models
hadronic
decay
radioactive decay
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other features
PrimGenAction
particle gun
RunAction
EventAction
output for analysis
SteppingAction
colour tracks
StackingAction
kill particles for speed
analysis
AIDA and PI
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Am241 source
g (59.5 keV)
a (5.49 MeV)
Am241
Np237 (92.7 keV)
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g
upwards
through
Xe shell
Pb compton
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n
room
elastic
inelastic
outside
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241Am spectrum
experimental
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g spectrum
experimental
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Time Constant Discrimination
Experimental Data
Geant4 Output

• Red Curve Alphas
• Blue Curve Gammas