e+e- Collider Detector - Design P

 

 

Component

Radius (cm)

Axial |Z| (cm)

 

Technology

 

Performance

Min

Max

Min

Max

 

Vertex Detectors

 

1

 

10

 

0

 

15

 

CCD

 

3.0 µ + 10µ/psin3/2&#;

 

Tracker

 

25

 

150

 

0

 

200

 

TPC

dP/P2 ~ 7 x 10 -5 high p

dP/P ~ 1.5 x 10 -3 low p

EM Calorimeter

Barrel

End Cap

 

150

25

 

185

150

 

0

205

 

235

240

 

Pb/scintillator or Liquid Argon

 

dE/E ~ 15%/&#;E + 1%

 

Magnet Coil

 

185

 

215

 

0

 

235

 

SC Solenoid

 

3.0 Tesla

Had Cal

Barrel

End Cap

 

215

25

 

295

175

 

0

240

 

320

320

 

Pb/scintillator

 

dE/E ~ 50%/&#;E + 2%

Iron/Muon Det/Tailcatcher

Barrel

End Cap

 

295

25

 

425

425

 

0

320

 

320

450

 

Iron Gas Chambers

 
Alternate Design would be to reduce the central tracker TPC radius to ~100 cm and to use the space between ~100 cm and 150 cm for a Particle I.D. system. The desirability of this should be studied. The arguments in favor of no Particle I.D. are that
  1. There will be some particle ID from dE/dx from a TPC (Aleph did quite well overall this way)
  2. Keeping the overall detector size the same, reducing the TPC radius, spoils the momentum resolution by a factor of ~ 2
  3. The particle ID system will degrade the resolution of the electromagnetic calorimeter somewhat. This could be an important factor in detection of H0 decaying to 2 gammas.
Vertex Detector
5 layers of CCD's, 20µ x 20µ pixels
Radius of layer
1 = 1.2 cm, &#; 2.5 cm long
2 = 2.4 cm, &#; 12.5 cm long
3 = 3.6 cm, &#; 12.5 cm long
4 = 4.8 cm, &#; 12.5 cm long
5 = 6.0 cm, &#; 12.5 cm long
Central Tracker
TPC, 150 cm radius &#; 2.0 meters long
assume 120 points/track
140µ point measuring accuracy
gas thickness 0.01 radiation length
Electromagnetic Calorimeter
32 layers of 4 mm lead plates or Liquid Argon with similar parameters
3 mm scintillator
Lead X0 = 0.56 cm, interaction length = 17 cm
total of 32 x 0.4 cm = 12.8 cm of Pb ~ 23 radiation lengths
segmentation 5 cm x 5 cm pads ~ 2 0 x 2 0
Single layer of silicon detector (or finer segmentation for Liquid Argon) at a depth of ~ 6 radiation length with fine segmentation (~ 1 cm?) for better spacial resolution to locate shower centroids. Hadronic Calorimeter
65 layers of 8 mm Lead plates
3 mm scintillator
segmentation 15 cm x 15 cm pads, ~ 4 0 x 4 0
Calorimeter thickness:
Electromagnetic 12.8 cm of Pb = 0.75 interaction lengths
Hadronic 52 cm of Pb = 3.1 interaction lengths
Total 3.85 interaction lengths + 6 interaction lengths in iron of tailcatcher in Muon detector
Muon Detector
10 Iron plates, 10 cm thick each
2 cm gap between plates with gas chambers
continue pad structure to serve as calorimetry tail catcher
Strip read out with 1 cm resolution for muon tracking
All layers to have strips parallel to beam direction
2 layers to have transverse strips to measure Z
Superconducting Coil
3.0 Tesla field
1 interaction length thick