Particle Detectors - physi.uni-heidelberg.demenzemer/PP_SS2012/Detectors_4.pdf · gas amplification...
Transcript of Particle Detectors - physi.uni-heidelberg.demenzemer/PP_SS2012/Detectors_4.pdf · gas amplification...
Particle Detectors
27.04.2012
CMS Hadronic Calorimeter
Sampling Calorimeter, samples fraction F of total energy; energy resolution degraded by 1/√F
Calorimeter resolution at the LHC
Charge Amplification in Gas Counters
Incident particle: electron
Multiwire-Proportional Chambers (MWPC)
Charpak, 1967/68Nobelpreis 1992
spatial resolution ~
typical wire distance: 2mm→
Limitation of MWPC
Driftchambers
time measurement → drift distance → location of particle trajectoryspatial resolution of about 100 μm
First drift chamber (1971): developed and constructed at PI operated at CERN
Have a look at JADE (e+ - e- collider experiment at DESY) jet chamber in INF 308!
Straw tube drift chambers of LHCb experiment
Physikalische Institut, NIKHEF, Warschau
5m long modules
Planar Geometry
Drift time relativeto anodes define pointson the track. A fit thusextraploates the tracktrajectory.
anodes
Track reconstruction with Babar Driftchamber
electrical signal
charged particle
Backplane (p doped)
Bulk (n doped)
readout strips/pixels (n+ doped)typical size 50 µm
readout electronics
bonding
Silicon Detector
CMS
Silicon Strip Detectors
LHCb
Silicon Pixel Detectors