1. R.S. Orr 2009 TRIUMF Summer Institute
Hadronic Calorimeters
Strong (nuclear) interaction cascade
Similar to EM shower
hadronic interaction length
Energy Resolution
shower fluctuations
leakage of energy
hadronic calorimeter
nearly always sampling calorimeters
invisible energy loss mechanisms
Shower length
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2. R.S. Orr 2009 TRIUMF Summer Institute
Sampling Calorimeter
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3. R.S. Orr 2009 TRIUMF Summer Institute
Hadronic Lateral Shower Profile
Hadronic shower much broader than EM Fe
Mean hadronic versus MCS Fe
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4. R.S. Orr 2009 TRIUMF Summer Institute
Hadronic Shower Longitudinal Development
ZEUS
Uranium/Scint
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5. R.S. Orr 2009 TRIUMF Summer Institute
Lateral Scaling with Material
90% containment does not scale
core scales
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6. R.S. Orr 2009 TRIUMF Summer Institute
Calorimeter Energy Resolution
sampling and shower fluctuations
energy
number of samples
energy deposited in a sampling step
stochastic term
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7. R.S. Orr 2009 TRIUMF Summer Institute
Calorimeter Energy Resolution
e.g. # of photo-electrons in PM, ion pairs in liquid argon
counting statics in sensor system
mean # of photo-electrons in PM per unit of incident energy
this term is usually negligible
shower leakage fluctuations – make calorimeter as deep as $$ allow
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8. R.S. Orr 2009 TRIUMF Summer Institute
Calorimeter Energy Resolution
important for low level signal
liquid argon electronics
detector capacitance
noise - detector or electronics
N channels with some intrinsic noise
noise (energy)
deposited energy
behaviour
increases with number of channels summed over
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9. R.S. Orr 2009 TRIUMF Summer Institute
Calorimeter Energy Resolution
inter - calibration uncertainty of channels
constant in E
fractional channel to channel gain uncertainty
spatial in-homogeneity of detector energy response
dead space
temperature variation
radiation damage
all these influence spatial variation of effective energy response
constant
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10. R.S. Orr 2009 TRIUMF Summer Institute
Calorimeter non-uniformity
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11. R.S. Orr 2009 TRIUMF Summer Institute
Generic Detector
Layers of Detector Systems around Collision Point
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12. R.S. Orr 2009 TRIUMF Summer Institute
Semi-empirical model of hadron shower development
hadronic part
electromagnetic part
radiation length
interaction length
- significant amount of material in front of calorimeter (magnet coil etc.)
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13. R.S. Orr 2009 TRIUMF Summer Institute
More Rules of Thumb for the Hobbyist
Mixtures in sampling calorimeters
Shower maximum
active + passive material
95% Longitudinal containment
95% Lateral containment
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14. Typical Calorimeter Resolutions
Homogeneous EM (crystal, glass)
CLEO, Crystal Ball, Belle, CMS.....
Sampling EM (Pb/Scint, Pb/LAr)
CDF, ZEUS, ALEPH, ATLAS.....
Non-compensating HAD (Fe/Scint, Fe/LAr)
CDF,ATLAS,H1, LEP = everyone
Compensating HAD (DU/Scint)
ZEUS, HELIOS
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15. R.S. Orr 2009 TRIUMF Summer Institute
Invisible Energy in Hadronic Showers
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16. R.S. Orr 2009 TRIUMF Summer Institute
Difference in Response to Electrons and Hadrons
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17. R.S. Orr 2009 TRIUMF Summer Institute
Effect of e/h on Energy Resolution
Resolution tail
Fe/Scint
DU/Scint
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18. R.S. Orr 2009 TRIUMF Summer Institute
Effect of e/h on Linearity
Fe/Scint
DU/Scint
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19. R.S. Orr 2009 TRIUMF Summer Institute19

20. R.S. Orr 2009 TRIUMF Summer Institute
Weighting to Correct for e/h
Energy resolution does not improve
Weight down EM part of shower
tune
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21. R.S. Orr 2009 TRIUMF Summer Institute
Jet Energy Resolution
Jet-jet Mass Resolution
Fluctuations between EM and Hadronic component in jets will degrade the energy resolution for jets
Effects other than e/h dominate the 2-jet mass resoluton
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22. R.S. Orr 2009 TRIUMF Summer Institute
Jet-Jet Mass Resolutions
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23. R.S. Orr 2009 TRIUMF Summer Institute
Conceptual Readout Schemes
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24. R.S. Orr 2009 TRIUMF Summer Institute
ZEUS Forward Calorimeter
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25. R.S. Orr 2009 TRIUMF Summer Institute25

26. R.S. Orr 2009 TRIUMF Summer Institute
Generic Detector
Layers of Detector Systems around Collision Point
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27. LAr Calorimetry Five different detector technologies
Calorimetry coverage to
SM Higgs Discovery Potential
EM Calorimeter
Hadronic & Forward
Calorimeters
EM Calorimeter
WW Fusion
Tag jets in Forward Cal 27

28. LAr Calorimeter Technology Overview
Design Goals Technology
EM Calorimeters ( ) and Presampler ( )
Hadronic Endcap ( )
Forward Calorimeter ( )
Lead/Copper-Kapton/Liquid Argon Accordion Structure
Copper/Copper-Kapton/Liquid Argon Plate Structure
Tungsten/Copper/Liquid Argon Paraxial Rod Structure 28

29. LAr and Tile Calorimeters
Tile barrel
Tile extended barrel
LAr hadronic
end-cap (HEC)
LAr EM end-cap (EMEC)
LAr EM barrel
LAr forward calorimeter (FCAL) 29

30. Electromagnetic Barrel
Barrel Module Schematic
with presampler
Half Barrel Assembly
2x16 modules
I.R/O.R 1470/2000 mm
3 longitudinal samples
presampler
64 gaps /module
2.1 mm gap
2x3100 mm long
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31. R.S. Orr 2009 TRIUMF Summer Institute
Electromagnetic Endcap
2x8 modules
Diam mm
3 longitudinal samples
Front sampling of 6
for ,  - strips.
96 gaps /module outer wheel
32 gaps/module inner wheel
mm gap outer
mm inner
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32. R.S. Orr 2009 TRIUMF Summer Institute
Accordion Structure
Pb Absorber
Honeycomb spacer
&
Cu/Kapton electrode
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33. R.S. Orr 2009 TRIUMF Summer Institute
Prototype of EM endcap
Detail of Kaptons
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34. R.S. Orr 2009 TRIUMF Summer Institute
ATLAS FCAL
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35. Pictures of assembly process

36. LAr Forward Calorimeters
FCAL C assembly into tube – Fall 2003 36

37. Liquid Argon Gap
Tungsten Rod

38. R.S. Orr 2009 TRIUMF Summer Institute
ATLAS HEC Structure
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39. Transformer matching
Does not work in magnetic field. Long readout cables slow down signal
Large capacitance, large noise
EST
Works in magnetic field
Low capacitance

40. Hadronic Endcap Calorimeter (HEC)
Front Wheel
Rear Wheel
Wheel Assembly
Composed of 2 wheels per end
Front wheel: 67 t 25 mm Cu plates
Back wheel: 90 t 50 mm Cu plates 40

41. Oct 2002 41

42. 42

43. Electromagnetic Endcap43

44. Hadronic Endcap 44

45. HEC – FCAL Assembly 45

46. Test Beam Single Particle Energy Resolution
Noise subtracted energy resolution

47. Noise Level in LAr Calorimeters
Since the FCal is in the very forward region, these noise levels are OK

48. Signal Shape before startup

49. Lar Endcap Installed in ATLAS49