Talking About Present Status and Plans for CMS Atlas
Slide 1
Talking about present status and plans for CMS Atlas
2300 physicist/engineers of CMS
1800 physicist/engineers of Atlas
Work begun on experiments 12 years ago
Typical single minimum bias event
Slide 2
The two major detectors on LHC to scale
Both share very similar subsystems
Major difference is choice of magnetic field
Atlas:
relatively small central solenoid (2t)
Calorimetry outside solenoid.
Precision muon measurement in large toroidal field (40% cost)
CMS:
Large central solenoid (4t) (25% cost)
Calorimetry inside solenoid.
Muon system measurements in return yoke.
Slide 3
Schedule of CMS run by LHC Civil engineering
Atlas hall habitable for over 1.5 years
CMS hall ready for occupancy Oct 1, 2007
Atlas being in final resting place
CMS being build above ground. Need to cable starting now.
Slide 4
CMS build around world’s largest solenoid
4T central field
2.7 GigaJoules stored energy
Cool down successful
Reached B=4.003T 2 weeks ago
Test dumping of 2.7 Gigajoules. Superconducting coils go normal.
Helium changes phase. $10000 done three times
Exciting times at CERN.
Magnet ready.
Slide 5
Atlas build around toroids
4-8 Tm bending power
Cooled down. Testing measuring magnet field right now.
Will obviously be ready.
Slide 6
Give status of detector from interaction outward
CMS tracking in 4 T magnetic field.
Thousands of tracks to reconstruct.
80 million tracking elements (200x LEP detectors)
pixels near center (good virtex position resolution)
Slide 7
Silicon detectors in hand
Integration in device well underway.
Installation early next year.
In good shape. Pixels installed after Nov 08 pilot run.
Slide 8
Atlas system similar. Pixels, Silicon strips.
Straw tube (TRD) pi0/gamma separation
Completely finished.
Slide 9
Monte carlo of muon momentum resolution for two detectors
CMS mult scattering in iron return yoke limits muon system
Resolution central detector (B=4T dominates)
Atlas resolution in Toroids Dominate.
CMS combined sightly better, Time will tell
Slide 10
Inside magnet
CMS opted for crystals to measure e’s, and gamma’s
80,0000 crystals in system
Presample 3x rejection pi0/gamma
Slide 11
Crystals need to be grown, Russia, China
Barrel Complete April 2007
Famous plot within collaboration
Endcaps get crystals starting now.
Production schedule tight.
Won’t be ready for commissioning run (shown in red)
Ready for physics
Slide 12
Outside solenoid
Atlas uses liquid argon/Pb ECAL
CMS almost factor of 2 better resolution
Further consequences later
Slide 13
Inside solenoid
CMS endcap and barrel calorimeter stacked
Scintillator brass tiles, WLS fiber readout
15,000 channels (3 radial segmens)
Good position
Picture of being stacked
Coverage
Slide 14
Barrel to be inserted in magnet
Endcap known as the Nose
Both detectors and electronics done/operational
Slide 15
Outside magnet
Barrel Fe-Scint, endcap Cu-argon
Installed/Working
Slide 16
Measured HCAL resolution
Atlas factor of 2 better
CMS crystals -> non compensating HCAL
Pay for good gamma, e resolution
Slide 17
CMS Barrel Muon System made of 3 subsystems
Drift Chambers 200k channels 200um resolution
Complete Dec 6
Slide 18
CMS Endcap Muon CSC
Self advertisement, OSU build Cathode FE electronics,
Data Aquistion electronics (4 boards) 5/8 main electronics
Boards in system
Active area size of football field. With good resolution
90% installed and commissioned
Slide 19
Nice cosmic ray going through both chambers
Track resolution confirmed
Have been exercising for a long time.
Slide 20
Both CSM and Atlas have RPC. Good alternative
To scint counters. Course position, good timing,
Back up trigger. Complete Dec06.
Slide 21
Atlas MDT cover most area. CSC most forward (rate)
Trigger chambers. Done by Summer 2006
Slide 22
Atlas short. Slides given to me. Understanding of detector.
Toroids inspired us all with awe.
Impossible to do justice with pictures.
Slide 23
Trigger systems quite complex both AtlasCMS
Reduce input by 7 orders of magnitude.
Rate off chamber matches www world bandwidth
First Level Trigger reduces this to 100kHz
Farm Reduces this to 100 Hz
Slide 24
Whole talk required for trigger, Most system present. Extra
Capability summer 07. Second level trigger is large farm.
First 600 PC’s just purchased and will be installed at
Point 5 december.
Slide 25
Even at 100Hz data storage is incredible. Unthinkable 5 years ago.
CMS Atlas each produce on order of 20TB/day
Castor easily writes to tape 5x this amount
Distribution: Tier 1 and 2 centers
30 TB/day, with delay ok
Slide 26
All components on CMS and Atlas have undergone extensive
Tests. Every amplifier. Test beam. Radiation tests. Rate tests.
Continuity tests. One has to make them work together.
Slide 27
Both experiments are testing chambers using cosmic rays and test beam
Global test CMS
Test Mechanical, Infrastructure, Software, Trigger, DAQ
Slide 28
Special tracker module with Slicon detectors
Slide 29 First closing. Few problems. Couple of alignment
devices smashed.
Slide 30
Beautiful cosmic ray events passing though all detectors. Large
Trigger rate 200 Hz. Analysing and fitting data as we speak.
Slide 31
Atlas well toward being fully installed
CMS moves to new come. A lot to do.
In 8-9 months
Slide 32
LHC schedule.
Delivery of magnets on schedual.
Impossible to fully commission all magnets for 7TeV running.
Will commission ¼ other ¾ in Nov to May break
Will run at 900 GeV CM
Three stages
Random bunches, 75 nsec bx interval, 25 nsec bx interval
1x29-2e33
Slide 33
A commissioning run. Luminosity probably on the low side.
Few W’s and Z’s . Lots of min bias events with single muons
p>100 Gev.
We have lots to understand
Slide 34 When we turn on we are not fully working. Timing, calibration,…
Worked out from testbeam,pulsers, cosmic rays. Improve all of these
With clean beam
Slide 35 Once working look at well know signals. Measure well known
Cross sections. Commission detector is making sense.
Slide 36 To see what we might likely see look at CDF commission Tevatron II 2002.
Slide 37 When LHC turns on, it is expected to have reasonable luminosity
Higgs at 200GeV, Susy at 1TeV 1st year
Super LHC installed 2013.
Slide 38 Atlas and CMS will be ready for physics run May 2008