Outline

1
Outline

• Electromagnetic showers
• Shower Development
• Characteristics of showers
• Shower Detectors
• DHCal
• Design Concept
• Conclusion

2
Electromagnetic Showers

• Electrons with energies gt 100MeV lose energy
  almost entirely through bremsstrahlung
• ? e e-
• (Pair Production)

3
e
?
e-
e-
e
0
1
2
3
4
Characteristics

• N(t) etln2
• tmax ln(Eo/E)/ln2
• L ? E0/E
• Showers are statistical in nature

5
Shower detectors

• Calorimeters measure the total energy deposited
• Two types Electromagnetic and Hadronic
• tmax 3.9 lnEo
• The total energy is measured by counting the
  number of particles in the shower whose energy
  exceeds certain value

6
Hadronic Showers

• Transverse momentum 350MeV/c Hence hadronic
  showers are more spread out.
• Most of the energy dissipated is by ionization
  losses and secondary protons
• ?o ? 2 ? (leading to showers)

7
DHCal
8
From CERN-open-2000-344, A. Sharma
9
Initial design concept for gas amplification DHCAL
10
CERN GDD Group electron-micrograph of GEM foil
hole
11
Conclusion

• Study of various technologies
• Construction of mechanical prototypes
• Construction of multi layer prototype