Particle Detectors - Grupen & Shwartz - Cern

250 8 Calorimetry
wavelength
shifter
14 X 0 electron shower readout
3.2 λ a hadron shower readout
40 cm
40.5
cm
photomultiplier
Fig. 8.14. Typical set-up of an iron–scintillator calorimeter with wavelengthshifter
readout [50].
π 0
0
K L
π 0
0
KS Fig. 8.15. Sketch of a hadron cascade in an absorber.
Apart from the larger longitudinal development of hadron cascades,
their lateral width is also sizably increased compared to electron cascades.
While the lateral structure of electron showers is mainly determined by
multiple scattering, in hadron cascades it is caused by large transverse
momentum transfers in nuclear interactions. Typical processes in a hadron
cascade are shown in Fig. 8.15.
Different structures of 250 GeV photon- and proton-induced cascades in
the Earth’s atmosphere are clearly visible from Fig. 8.16 [51]. The results
shown in this case were obtained from a Monte Carlo simulation.
π 0
n
μ
μ
ν μ
ν μ