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C. W. Fabjan and D. Fournier
Table 6.5 Parameters of the ATLAS and CMS hadronic calorimeter facilities
ATLAS
CMS
Technolgy [ηhalf-coverage]
Barrel/Ext. barrel 14 mm Fe/3 mm scint. [0–1.4]
50 mm brass/4 mm scint. [0–1.4]
End-caps
25 mm (front) − 50 mm (back)
Cu/8.5 mm LAr [1.4–3.2]
80 mm brass/4 mm scint. [1.4–3.0]
Forward
Cu (front) − W (back)/0.25–0.50
LAr [3.2–4.9]
4.4 mm steel/0.6 mm quartz
[3.0–5.0]
Channels
Barrel/Ext. barrel 9852
2592
End-caps
5632
2592
Forward
3524
1728
Granularity (
Barrel/Ext. barrel 0.1 × 0.1 to 0.2 × 0.1
0.087 × 0.087
End-caps
0.1 × 0.1 to 0.2 × 0.2
0.087 × 0.087 to 0.35 × 0.028
Forward
0.2 × 0.2
0.175 × 0.175
Longitudinal samplings
Barrel/Ext. barrel Three
One
End-caps
Four
Two
Forward
Three
Two
Absorption lengths
Barrel/Ext. barrel 9.7–13.0
5.8–10.3
10–14 (with coil/HO)
End-caps
9.7–12.5
9.0–10.0
Forward
9.5–10.5
9.8
One promising direction is being pursued by the DREAM Collaboration [144].
DREAM (‘Dual REAdout Method’) is a concept aiming at event-by-event separate
detection of the electromagnetic component through Cherenkov light and the
hadronic showers through scintillation light. Timing information might provide
an additional handle to disentangle the various processes (e.g. delayed nuclear
photon emission). The combined information could in principle allow complete
reconstruction of the shower- and jet composition. The LC jet benchmark resolution
of σ/E ≈ 0.30/
√
E might not remain a dream [84].
The CALICE (Calorimeters for the Linear Collider Experiment) Collaboration
aims at the same performance: it makes the concept of Particle Flow Analysis an
integral part of the design concept of the experimental facility aiming to separately
measure the momenta of the charged component, photons in the electromagnetic
and neutral hadrons (n, K 0 ) in the hadron calorimeter. The calorimeter is placed at
a relatively large radius allowing the jets to open and charged and neutral particles
to separate in the strong B-field. This strategy requires exceedingly high granularity
(more than 10 8 channels) to measure the individual shower profiles [65].
Besides studies for a possible LC a vigorous programme has been intiated to
undertand the physics potential and consequences for experimentation at a possible
C. W. Fabjan and D. Fournier
Table 6.5 Parameters of the ATLAS and CMS hadronic calorimeter facilities
ATLAS
CMS
Technolgy [ηhalf-coverage]
Barrel/Ext. barrel 14 mm Fe/3 mm scint. [0–1.4]
50 mm brass/4 mm scint. [0–1.4]
End-caps
25 mm (front) − 50 mm (back)
Cu/8.5 mm LAr [1.4–3.2]
80 mm brass/4 mm scint. [1.4–3.0]
Forward
Cu (front) − W (back)/0.25–0.50
LAr [3.2–4.9]
4.4 mm steel/0.6 mm quartz
[3.0–5.0]
Channels
Barrel/Ext. barrel 9852
2592
End-caps
5632
2592
Forward
3524
1728
Granularity (
Barrel/Ext. barrel 0.1 × 0.1 to 0.2 × 0.1
0.087 × 0.087
End-caps
0.1 × 0.1 to 0.2 × 0.2
0.087 × 0.087 to 0.35 × 0.028
Forward
0.2 × 0.2
0.175 × 0.175
Longitudinal samplings
Barrel/Ext. barrel Three
One
End-caps
Four
Two
Forward
Three
Two
Absorption lengths
Barrel/Ext. barrel 9.7–13.0
5.8–10.3
10–14 (with coil/HO)
End-caps
9.7–12.5
9.0–10.0
Forward
9.5–10.5
9.8
One promising direction is being pursued by the DREAM Collaboration [144].
DREAM (‘Dual REAdout Method’) is a concept aiming at event-by-event separate
detection of the electromagnetic component through Cherenkov light and the
hadronic showers through scintillation light. Timing information might provide
an additional handle to disentangle the various processes (e.g. delayed nuclear
photon emission). The combined information could in principle allow complete
reconstruction of the shower- and jet composition. The LC jet benchmark resolution
of σ/E ≈ 0.30/
√
E might not remain a dream [84].
The CALICE (Calorimeters for the Linear Collider Experiment) Collaboration
aims at the same performance: it makes the concept of Particle Flow Analysis an
integral part of the design concept of the experimental facility aiming to separately
measure the momenta of the charged component, photons in the electromagnetic
and neutral hadrons (n, K 0 ) in the hadron calorimeter. The calorimeter is placed at
a relatively large radius allowing the jets to open and charged and neutral particles
to separate in the strong B-field. This strategy requires exceedingly high granularity
(more than 10 8 channels) to measure the individual shower profiles [65].
Besides studies for a possible LC a vigorous programme has been intiated to
undertand the physics potential and consequences for experimentation at a possible