The CMS Construction - Infn
The CMS Construction - Infn
The CMS Construction - Infn
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<strong>The</strong> <strong>CMS</strong> <strong>Construction</strong>
(<strong>CMS</strong>) Design Criteria<br />
Very good muon identification and momentum<br />
measurement<br />
Trigger efficiently and measure sign of TeV muons dp/p < 10%<br />
High energy resolution electromagnetic calorimetry<br />
~ 0.5% @ E T ~ 50 GeV<br />
Powerful inner tracking systems<br />
Momentum resolution a factor 10 better than at LEP<br />
Hermetic calorimetry<br />
Good missing E T resolution<br />
(Affordable detector)<br />
Transparency from<br />
the early 90’s
High Interaction Rate<br />
Experimental Challenge<br />
LHC Detectors (especially ATLAS, <strong>CMS</strong>) are radically<br />
different from the ones from the previous generations<br />
pp interaction rate 1 billion interactions/s<br />
Data can be recorded for only ~10 2 out of 40 million crossings/sec<br />
Level-1 trigger decision takes ~2-3 μs<br />
electronics need to store data locally (pipelining)<br />
Large Particle Multiplicity<br />
~ superposed events in each crossing<br />
~ 1000 tracks stream into the detector every 25 ns<br />
need highly granular detectors with good time resolution for low occupancy<br />
large number of channels (~ 100 M ch)<br />
High Radiation Levels<br />
radiation hard (tolerant) detectors and electronics
<strong>The</strong> <strong>CMS</strong> Detector
<strong>The</strong> <strong>CMS</strong> Collaboration (2007)<br />
Member States<br />
Non-Member States<br />
USA<br />
Total<br />
Member States<br />
Non-Member States<br />
USA<br />
Total<br />
Number of<br />
Laboratories<br />
59<br />
67<br />
49<br />
175<br />
# Scientific<br />
Authors<br />
1084<br />
503<br />
723<br />
2310<br />
Associated Institutes<br />
Number of Scientists<br />
Number of Laboratories<br />
Oct. 3rd 2007/gm<br />
62<br />
9<br />
Uzbekistan<br />
Russia<br />
USA<br />
Austria<br />
Belgium<br />
CERN<br />
France<br />
Bulgaria<br />
Italy<br />
Finland<br />
Ukraine<br />
Georgia<br />
Belarus<br />
UK<br />
Poland<br />
Armenia<br />
Portugal<br />
Turkey<br />
Brazil<br />
Serbia<br />
China, PR Spain<br />
Pakistan<br />
China (Taiwan)<br />
Lithuania<br />
Switzerland<br />
Mexico<br />
Korea<br />
Iran Colombia<br />
New-Zealand<br />
Croatia<br />
Ireland India Cyprus<br />
Estonia<br />
2310 Scientific Authors<br />
38 Countries<br />
175 Institutions<br />
Germany<br />
Greece<br />
Hungary
Exploded View of <strong>CMS</strong><br />
Plus Side<br />
Minus Side
Assembly of Iron Yoke<br />
2003
Assembly of the Coil
Assembly of the Coil<br />
Sept 05<br />
Coil: 230 tons<br />
Outer vacuum tank:<br />
13 m long SS tube, φ=7.6 m
Surface Hall: Barrel Muons
Lowering of Heavy Elements<br />
YE+1 (Jan’07)
Lowering of Heavy Elements<br />
Feb 2007
Insertion of Barrel ECAL<br />
Jul’07
Completion of Services on YB0<br />
Nov. ‘07
Dic. ‘07<br />
Lowering of Tracker
Dic. ‘07<br />
Tracker Insertion
Dic. ‘07<br />
Tracker in <strong>CMS</strong>
Extreme engineering: 4T, big dimensions & large magnetic deformation<br />
E/M (kJ/kg)<br />
12.0<br />
10.0<br />
8.0<br />
6.0<br />
4.0<br />
2.0<br />
0.0<br />
ZEUS<br />
TOPAZ<br />
SDC-model<br />
ATLAS -sol.<br />
ALEPH<br />
CDF<br />
H1<br />
CLEO2<br />
DELPHI<br />
VENUS<br />
<strong>The</strong> <strong>CMS</strong> SC Solenoid<br />
Design Goal: Measure 1 TeV/c muons with < 10% resolution<br />
5 modules Φ 6900 mm ; L 2500 mm ; W= 50 t<br />
ATLAS End-caps<br />
10 100 1000 10000<br />
Stored Energy (MJ)<br />
<strong>CMS</strong><br />
ATLAS Barrel<br />
Solenoid composed by<br />
5 modules<br />
(CB-2, CB-1, CB0,<br />
CB+1, CB+2)<br />
I = 20kA
Winding of the Coil<br />
Specific winding technology developed by INFN Genova<br />
in collaboration with Ansaldo Superconduttori<br />
Winding
24 July<br />
Test of the Magnet (2006)<br />
Magnet Current Cycles achieved<br />
during August<br />
28 August<br />
19 kA, 4 Tesla!<br />
2 days<br />
stable<br />
operation<br />
at 3.8 T
Tracking at LHC<br />
Need factor 10 better momentum resolution than at LEP<br />
1000 particles emerging every crossing (25ns)<br />
Fluence over<br />
10 years of<br />
LHC<br />
Operation
Layout of <strong>CMS</strong> Tracking<br />
120 cm<br />
<strong>CMS</strong><br />
TOB<br />
TEC<br />
TIB<br />
TID<br />
Pix<br />
300 cm<br />
Si pixels surrounded by silicon strip detectors<br />
Pixels: ~ 1 m 2 of silicon sensors, 65 M pixels, 100x150 μm 2 , r = 4, 7, 11 cm<br />
Si μstrips : 223 m 2 of silicon sensors, 10 M strips, 10 pts, r = 20 – 120 cm
<strong>The</strong> <strong>CMS</strong> Tracker<br />
• Pixel<br />
• Silicon Strip Tracker<br />
Largest Silicon Strip Detector<br />
ever built:<br />
~200m 2 of silicon,<br />
instrumented volume ~24m 3<br />
TIB (4 layers )<br />
TID (3 disks, 3 rings )<br />
TOB (6 layers)<br />
TEC (9 disks, 7 rings )
Si Modules and Electronics Chain<br />
Si Sensors<br />
Ride on<br />
technology wave<br />
75k chips using<br />
0.25μm technology<br />
Detector<br />
TTCrx<br />
CLK<br />
CCU<br />
Tx/Rx<br />
Tx/Rx<br />
T1<br />
I2C<br />
Control<br />
module<br />
digital<br />
optical<br />
link<br />
μP<br />
PLL<br />
Front End Controller<br />
APV<br />
Optical<br />
transmitter<br />
<br />
<br />
<br />
<br />
analogue<br />
optical <br />
link <br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
ADC<br />
<br />
FPGA<br />
Front End Module<br />
TTCrx<br />
DCU<br />
256:1<br />
APV<br />
MUX<br />
FPGA<br />
RAM<br />
Front End Driver
System Components<br />
• Module<br />
<br />
Sensor + FE Hybrid<br />
• chip: APV25 (128 strips) - analog<br />
• Optical converter (AOH)<br />
<br />
one laser/fiber = 256 strips<br />
• Controls/Clock/Trigger<br />
<br />
<br />
Control chip (CCU)<br />
• I2C protocol with modules<br />
• rings of CCUs<br />
Digital optical converted (DOH)<br />
• optical link to VME controller (FEC)<br />
Hybrid+AOH<br />
Controls<br />
String
System Components<br />
Modules (all)<br />
AOH (Perugia)<br />
DOM (Firenze)<br />
CCUM (Cern)<br />
Mother cable (Bari)
<strong>The</strong> Start of the TIB Integration<br />
Apr. ‘05<br />
<strong>The</strong> first string
Si Tracker<br />
TIB<br />
TEC
Si Tracker
Si Tracker
Tracker Readied for Installation<br />
Dead channels ~ 0.5 ‰ stable in time<br />
Noisy channels ~ 0.5 % stable in time
Lead Tungstate ECAL<br />
Design Goal: Measure the energies of photons from a decay of<br />
the Higgs boson to precision of ≤ 0.5%<br />
<strong>CMS</strong> chose scintillating crystals<br />
To <strong>CMS</strong><br />
m 3<br />
10<br />
<strong>CMS</strong><br />
75000 PWO<br />
Cleo II<br />
7800 CsI(Tl)<br />
Belle<br />
8816 CsI(Tl)<br />
From Crystal Ball<br />
5<br />
Babar<br />
6580 CsI(Tl)<br />
Crystal Ball<br />
672 NaI(Tl)<br />
L3<br />
12000 BGO<br />
Crystal Barrel<br />
1380 CsI(Tl)<br />
TAPS<br />
600 BaF2<br />
KTeV<br />
3100 CsI<br />
Alice<br />
17920 PWO<br />
P. Lecoq<br />
1972<br />
1985<br />
1986<br />
1989<br />
1990<br />
1999<br />
2008
<strong>CMS</strong> Requests and PWO<br />
To comply with LHC and <strong>CMS</strong><br />
conditions ECAL must be:<br />
• fast<br />
• compact<br />
• highly segmented<br />
• radiation resistant<br />
1995 1998<br />
2<br />
T dependent: -2%/°C<br />
Very low light output<br />
Very effective in high<br />
energy γ containment
ECAL layout<br />
PWO: PbWO 4<br />
about 10 m 3 , 90 t<br />
barrel cystals<br />
Pb/Si<br />
preshower<br />
Barrel: |η| < 1.48<br />
Barrel: | < 1.48<br />
36 Super Modules<br />
61200 crystals (2x2x23cm(<br />
2x2x23cm 3 )<br />
barrel<br />
Super Module<br />
(1700 crystals)<br />
endcap<br />
supercystals<br />
(5x5 crystals)<br />
EndCap “Dee”<br />
3662 crystals<br />
EndCaps: 1.48 < |η| | | < 3.0<br />
4 Dees<br />
14648 crystals (3x3x22cm<br />
(3x3x22cm 3 )
Choice of the Photodetector<br />
20<br />
d eff ~6μm<br />
40μm<br />
Avalanche photodiodes (APD)<br />
Two 5x5 mm 2 APDs/crystal<br />
- Gain: 50 QE: ~75% @ λ peak = 420 nm<br />
- Temperature dependence: -2.4%/ O C<br />
- Gain dependence on bias V: 3%/V
PWO Production<br />
BARREL ingot<br />
EE INGOT<br />
ENDCAPS ingots<br />
Delivered Barrel crystals<br />
63000<br />
61000<br />
59000<br />
57000<br />
55000<br />
53000<br />
51000<br />
49000<br />
47000<br />
45000<br />
BARREL CRYSTALS ~ 1150 xl/m<br />
Dec-05 Mar-06 Jul-06 Oct-06 Jan-07 Apr-07
EB <strong>Construction</strong>: Regional Centers<br />
Submodule<br />
2x5 crystals<br />
Module<br />
400 crystals<br />
CERN Lab.27<br />
EP-CMA<br />
&<br />
Casaccia<br />
Assembly and test of modules in RC: ENDED in March 2007
INFN/ENEA Regional Center<br />
Check crystals in Rome RC<br />
Glue subunits and check APD gain<br />
<strong>The</strong> first submodule!<br />
Y 2002<br />
<strong>The</strong> first module!
EB <strong>Construction</strong>: Super Modules<br />
Cooling and electronics integration: completion by May 2007<br />
Supermodule<br />
1700 crytsals<br />
Dead channels: 19/61200
Response to high energy electrons<br />
ECAL Performance<br />
0.5%<br />
Temperature Stability: ≤ 0.1 °C<br />
Light response stability: ≤ 0.1%
ECAL: Cosmics Signal in <strong>CMS</strong>
Layout of <strong>CMS</strong> Muon System<br />
250 DTs 468 CSCs 480 RPCs
Muon System: Drift Tubes<br />
42mm<br />
Wire<br />
Mylar<br />
Electrode<br />
Strip<br />
13 mm<br />
Spatial resolution:<br />
Single cell ∼ 200 μm<br />
Chamber ∼ 100 μm
DT Chambers Assembly<br />
Legnaro Assembly Hall<br />
Assembly of 250 DT chambers:<br />
70 Aachen, 70 Madrid<br />
70 Padova, 40 Torino<br />
•1 layer= 70 wires<br />
• 27 gluing operations/chamber<br />
• 1 gluing operation = 1 day<br />
Precision of 100 μm over 5-10 m 2<br />
Torino Assembly Hall
Muon System: Start of Installation<br />
First installation Aug.03<br />
CERN ISR<br />
Salvato<br />
First installation test Aug. 2002<br />
Peghin
Muon System Completed<br />
ISTALLATION OF THE LAST<br />
OF THE 250 DT CHAMBERS<br />
IN THE CAVERN. IN WHEEL<br />
YB0<br />
26 Oct. 2007
Muon System: YB0 DTs in Operation!<br />
30Hz<br />
S03<br />
15Hz<br />
S01<br />
3Hz<br />
S12<br />
10Hz<br />
17Hz<br />
S11
Muon System: Resistive Plate Chambers<br />
Gas mixture<br />
95.5 C2H2F4<br />
95.5 C<br />
3.5 iC4H10<br />
0.3 SF6<br />
+ RH 50%<br />
Main Unit of a RPC:<br />
Single Gap (SG)<br />
Two SG coupled with<br />
readout plane in between<br />
Main characteristics of the RPCs<br />
used in <strong>CMS</strong>:<br />
•Bakelite thickness: 2 mm<br />
•Bakelite bulk resistivity :<br />
2-6 10 10 Ωcm<br />
• Gas Gap width: 2 mm<br />
•Operating voltage: 9.2-9.8 kV
RPC chamber layout<br />
480 RPCs coupled with DTs and inserted<br />
into the iron return yoke of the magnet<br />
RB4 120 chambers (2 double gaps/chamber)<br />
RB3 120 chambers (2 double gaps/chamber)<br />
RB2 60 chambers (2 double gaps/chamber) +<br />
60 chambers (3 double gaps/chamber)<br />
RB1 120 chambers (2 double gaps/chamber)<br />
Forward UP<br />
Backward UP<br />
Double<br />
Gap DG<br />
Double<br />
Gap DG<br />
Forward Down<br />
Backward Down
RPC Performance<br />
Cluster size<br />
Efficiency<br />
Counting rate<br />
All parameters are<br />
compatible with the<br />
results obtained during<br />
the production tests
RPC: First Events in <strong>CMS</strong>
First Closure of the <strong>CMS</strong> Experiment<br />
(2006)
Magnet Test & Cosmic Challenge<br />
(MTCC)<br />
ECAL<br />
Magnet<br />
HCAL<br />
Tracker<br />
Muon chambers
Run 2605 / Event 3981 / B 3.8 T / 27.08.06
Cosmics in the Tracker (Bat 186)<br />
A cosmic at -15°C<br />
Validated clusters shown<br />
Example of Performance<br />
Normal Strips 99.852 %<br />
(241 313 Strips)<br />
Dead Strips 0.116 %<br />
(275 Strips)<br />
Noisy Strips 0.032 %<br />
(76 Strips)<br />
•<strong>The</strong> Quality of the <strong>CMS</strong> Tracker is Excellent:<br />
• Dead or Noisy Strips < 3 / 1000<br />
• Signal: Noise > 25:1 in Peak Readout Mode<br />
• Enormous experience gained in operating the Tracker at TIF
Performance of <strong>CMS</strong>: Overview<br />
Tracking<br />
HCAL<br />
b-tagging
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