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