Post on 11-May-2018
transcript
TheCMSExperiment
• CurrentstatusandreviewofperformancegiveninEttoreFocardi’stalkonFriday14:00
TRAC2011‐H.W.K.Cheung 4 Muon Barrel
Tracker (Pixels and Strips)
EM Calorimeter Hadron Calorimeter
Muon Endcaps
Forward Calorimeter
Beam Scintillator Counters
CASTOR
ZDC
Ofcourse,thenormalexpectedproblems
• Usual:Notallchannelsareworking,e.g.forpixeldetector
5TRAC2011‐H.W.K.Cheung
Slowpanels:5/192
TooLowsignalamplitude(TBM):1/192(0.5%)
OneROCno‐signal:1/192(0.5%)Recoverable.
Nosignaloutput:1/192(0.5%)
NoI2CcommunicaSonwithAOH:6/192(3.1%)
Somelessexpectedproblems
• BeamgasinteractionsinthestraightsessionoftheLHCclosetotheexperimentgeneratesshowerofparticlesthatenterthepixeldetectoralongthebeamline.(“PKAMevents”)
• Largenumberofpixelsabovethresholdinthebarrelifthetrackhitsthesensor,generatingmanyhitsinasinglereadoutchannelcausingtimeouts.
• Visiblesinceearly900GeVcollisionsandscaleswithbeamintensity.
• ImplementednewFED`irmwaretodumpthelongeventsandholdofftriggers.Initiallytooksometimetounderstandtheproblem.
TRAC2011‐H.W.K.Cheung 6
Somelessexpectedproblems
• AnomalousECALSignals
• In collision data we observe anomalous signals in barrel ECAL where the readout is by APD (avalanche photodiode), having the appearance of large energy deposits in a single crystal.
• The origin of the signal is energy deposited by heavily ionizing particles in the APD.
• At the cluster level the anomalous signals appear as energy in a single crystal, while in e.m. showers the energy is typically shared between neighbouring crystals. This fact is used to tag anomalous signals.
7TRAC2011‐H.W.K.Cheung
MCwithoutsimulatingAPDhits
FocusonissuesrelevanttoupgradesforPhase1
• Old10yearplan:luminositypro`ile(fromJuly2010)• 2/3rdofdatacollectedinPhase1willbewith>1034cm‐2s‐1
• CMSdesignedfor1034cm‐2s‐1;Limitationsoperatingabovethis
• UpgradetoCMStomaintainperformance
8TRAC2011‐H.W.K.Cheung
Phase1
Phase2
Upgradewithconstraintsimposedbyrunningexperiment,maybewith“discovery
inprogress”
Luminosityand“Pileup”
• Interactionspercrossing• LHCdesignluminosityis1034cm‐2s‐1
• Totalinelasticcross‐sectionat14TeVis~80mb• 1barn=10‐24cm2
• Totalppinteractionrateis=80×10‐27×1034=800M/s
• Theppcrossingrateis40MHz,<#interactions>/crossing~20
• Only2888outof3564“25nsbuckets”are`illed
• Actual<#interactions>/crossing~25(atpeak)
• Higherenergyisbetter…
9TRAC2011‐H.W.K.Cheung
25ns
LHC~27km
circumference
PartonluminosiSes
• FromChrisQuigg:http://lutece.fnal.gov/PartonLum/
10TRAC2011‐H.W.K.Cheung
10-2 10-1 100 10110-610-510-410-310-210-1100101102103104105106
Parto
n Lu
min
osity
[nb]
0.9 TeV2 TeV4 TeV6 TeV7 TeV10 TeV14 TeV
CTEQ6L1: gg
[TeV]10-2 10-1 100 101
[TeV]
10-610-510-410-310-210-1100101102103104105106
Parto
n Lu
min
osity
[nb]
0.9 TeV2 TeV4 TeV6 TeV7 TeV10 TeV14 TeV
CTEQ6L1: qq
UpgradetoMuonSystems
• Upgradedrivenbyeffectofpeakinstantaneousluminosityonmuontriggerandbymaintenance
TRAC2011‐H.W.K.Cheung 12
DT(barrel)
CSC(endcap)
RPC(barrelandendcap)
NewME4/2CSC
NewRE4RPC
WorkonME1/1andtrigger
ExtendetarangeofRPC
WorkonDTtriggerboards:ReplacefailingASICsinthetaboardswithFPGAs
(improvesresolution);recoverASICsforspares;movepartsoftriggertolowradiation/
magnetic`ieldregion
L1MuonRateLimitaSonsatHighLuminosity
TRAC2011‐H.W.K.Cheung 13
• Need3hitstoreduceL1rates(betterpTresolution),need4chamberstokeephighef`iciency
• Remove3‐to‐1gangingofME1/1tolowerL1rates
• ReplaceCSCtriggerboard(FPGA)toincreaseef`iciencyoverallCSCetarange
!
UpgradetoMuonCSCandRPCEndcaps
• Additional4thchamberforRPCincreasesRPCtriggeref`iciency
• ProjectedimprovementinmuonL1triggerfor2×1034cm‐2s‐1
• RPCTriggeroptimizedforhighef`iciency
TRAC2011‐H.W.K.Cheung 14
R&DforGEMextensionofRPCetarangeseetalks:PaulKarchinandTaniaMoulikonMonday
UpgradetoHadronCalorimeters
• Upgradedrivenbyeffectofpeakinstantaneousluminosity,robustness,ef`iciency,trigger
TRAC2011‐H.W.K.Cheung 15
HB+HB‐HE+HE‐
HF+HF‐
HO0 HO+1 HO+2HO‐1HO‐2
EB+EB‐EE+EE‐ Tracker
Super conducting coil
ReplaceHPDinHB/HE/HOwithSiPM
DepthsegmentationinHB/HE
Addtiming(TDC)toHB/HE
ReplacePMTwithMAPMTinHF
ReplacePMTwithmoreradiationtolerantPMTsin
CASTOR
Anomalous/NoiseSignalsinHB/HE/HO
• ElectronicsnoisefromtheHybridPhotoDiode(HPD)andReadoutBox(RBX)usedforHB,HE,andHO,(worseinHOdueto0.2‐0.3Tregion,needtorunatlowerHV)
• TheHPDhas18channels/device;Thereare4HPDsinaRBX
• HPDandRBXnoiseisrandomandtheoverlapwithphysicsisverylow,andHPD/RBXnoiseproducedistinctpatternsinHCAL
• Filtershavebeendevelopedmakinguseofhitpatterns,timing,pulseshape,andEMfraction
• ReplaceHPDwithSiliconPhotoMultiplier(SiPM)
• EssentialforHO;EnablesHB/HEupgradeforrobustandef`icientoperation
TRAC2011‐H.W.K.Cheung 16
!
HPD
SiPM
UpgradestoHBandHE
• SeeJakeAnderson’sSiPMHOupgradetalkonFriday
• SiPMprovidesmuchbetterS/Ntodealwithincreasedoccupancy(poorertimingdeterminationandisolation)
• CansplitsignaltoTDC(reducebackground/noisecontributions)• Cangivelongitudinalsegmentation(x4)forreadout
• Electronisolation(e/pi)andtriggering;muonisolationandid
• Compensateforradiationdamageinfront/innerpartofHE
TRAC2011‐H.W.K.Cheung 17
!
UsingtimingtocleanMETinCDF
UpgradestoHBandHE
• R&Dstillneeded
• SiPMspeci`ications(esp.rateforHE/HB)
• OptimizationofFE/electronics(readout,trigger,infrastructure)
• Simulationstudies
TRAC2011‐H.W.K.Cheung 18
!
Isolationef`iciencyforbackgroundjetsampleatlowlumi(2segments)
(x4)Segmentationoptionstostudy
Fiber Bundles
PMT Window
2004 Test beam
AnomalousSignalsinHF(ForwardCalorimeter)
• HFExtendsetacoveragefrom3to5;Fortaggingjets,missingET,anddeterminingluminosity(e.g.VBFHiggs,70%ofsignalhaveajet>30GeVinHF)
• Quartz`ibersiniron.Long`ibers:extendsforthefulllengthofHF.Short`ibers:startatadepthof22cmfromthefrontofHF(separatereadout)
• LowamountofCherenkovlightfromquartzreadout`ibers.CherenkovlightproducedbyinteractionsinthewindowoftheHFPMTs
• Glasswindowthicknessinthecenteris~1mmincreasingto~6.1mmontheedge
19TRAC2011‐H.W.K.Cheung
150GeVmuonlookslikea120GeVjet;seenintestbeamIncollisionrunning,canget“1TeVjet”PMTevents.Dominantsourcesaremuonsfromdecaysin`lightandhadronshowerpunchthrough
PMT Hits
ES (GeV) E
L (G
eV)
AnomalousSignalsinHF(ForwardCalorimeter)
• MostoftheHFPMThitscanbeidenti`iedbasedontheenergysharingbetweentheLongandShort`ibers.Filtershavebeendevelopedtoeffectivelyremoveanomaloussignalswithlittleimpactonrealenergydeposits.
• CantagPMTeventsof`linebutonlywith80%ef`iciency,notsuf`icientforveryrareprocesses
• Replacewiththinnerwindow(<1mm)MAPMT(4anodes);patternoflightusedtoejectPMTeventswith96%ef`iciencyintestbeam
20TRAC2011‐H.W.K.Cheung
!OtheranomalousHFpulsesfromscintillationinmirrorsleeve;sleevesreplacedJan.2011.Newconnectionwithnon‐scintillatingmaterialforupgrade.
UpgradedPixelDetectorReplacement
• Upgradedrivenbyinstantaneousluminosity,robustness,ef`iciency
• Pixelreadoutchip(ROC)justadequatefor1034cm‐2s‐1with4%(16%)dynamicdatalossat25ns(50ns)crossingtime(duetoreadoutlatencyandbuffer)• At2×1034cm‐2s‐1datalossis15%(50%)forcrossingtimeof25ns(50ns)
• Threehitcoveragenothermetic,leadingto10‐15%inef`iciencywhenrequiring3‐of‐3hitsinhighluminosityenvironment.ThislimitsHLTtrackingtriggeref`icienciesandslowstrackingalgorithm
• InnerregionsneedreplacementbeforetheendofPhase1when~350`b‐1datawillhavebeencollected
TRAC2011‐H.W.K.Cheung 21
3BPIXlayers
2FPIXdisks/side
UpgradedPixelDetectorReplacement
• ReplacewithnewpixeldetectorwithadditionallayerusingredesignedROC,andhigherBWreadoutandDC‐DCconverterstoreusecurrentcablesand`ibers
• ReducematerialbyusingCO2coolinginsteadofC6F14,lighterconstruction,andrelocatingservicesoutoftrackingvolume
• Smallerdiameterbeampipe;`irstlayerclosertoIP
TRAC2011‐H.W.K.Cheung 22
4thbarrellayerclosertostripdetectortohelpmitigateanylossesforinnerstriplayer
b Jet Efficiency0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
c/lig
ht J
et E
ffici
ency
-410
-310
-210
-110
1-1s-22E34 cm
(b)
light jet: Current pixel detector geometry light jet: Phase 1 upgrade geometryc-jet: Current pixel detector geometryc-jet: Phase 1 upgrade geometry
!-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
!ef
ficie
ncy
vs
0
0.2
0.4
0.6
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0.05
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0.15
0.2
0.25
0.3
tp
-110 1 10 210
tef
ficie
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vs p
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
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tp1 10 210
tfa
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p
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
(a) (b)
(c) (d)
-1s-22E34 cm
Current Geometry
Phase 1 Geometry
Current Geometry
Phase 1 Geometry
Current Geometry
Phase 1 Geometry
Current Geometry
Phase 1 Geometry
SimulaSonsofUpgradedPixelDetector
• SimulationswithGeant4for2×1034cms‐2s‐1@25nsincludingdatalossesinROC
TRAC2011‐H.W.K.Cheung 23
Trackingef`iciencyandtrackfakerates
b‐taggingperformance
>25%
20%gainintaggingb‐jetsatsame1%lightquarkmistag
SeeposterbyPratimaJindal,Friday/MondayinroomChicago6&7formoredetails
ReduceMaterialinUpgradedPixelDetector
• Affectstrackresolutionsandphotonconversions
TRAC2011‐H.W.K.Cheung 24
φTrack -3 -2 -1 0 1 2 3
m)
µTr
ansv
.Impa
ct P
aram
eter
Res
olut
ion
(
20
40
60
80
100
120
140
160 Data
Data
| < 0.4η 0.1) GeV/c, |± in (1.0 T
Simulation p
| < 0.4η 0.2) GeV/c, |± in (3.0 T
Simulation p
Data
Data
= 7 TeVsCMS preliminary 2010
Radiationlength
Nuclearinteractionlength
CurrentdetectorUpgradedetector
Canseeeffectof18coolingpipesinresolutionoflowmomentumtracks
R&Dinvolvedforallcomponents:ROCitselfanddigitalreadout;CO2coolingcomponentsandsystem;ASICforrad‐hardDC‐DCconverter;rad‐hardsensors;simulationoflayout
Phase1TriggerUpgrade
TRAC2011‐H.W.K.Cheung 25
!"#$%"&'()*)+,)-$.)
!"#$%"&'()*)/,)-$.)
• Upgradedrivenbyinstantaneousluminosity,othersubdetectors,robustness
• KeepL1at100KHz,soextradatatobehandledbyDAQ
• Regionalcalorimetertriggertousefullgranularityforinternalprocessing,andmoresophisticatedclusteringandisolationalgorithmstohandlehigherratesandcomplexevents(e.g.improvedpositionresolutionandtriggerperformance)
• NewinfrastructurebasedonμTCAforincreasedBW,maintenance,and`lexibility
• Upgradetomuontriggertohandleadditionchannels,plusfasterFPGA
at1034at1034
OtherSubsystemUpgrades
• UpgradetoDAQtoaddresslargerdatasizesandreadoutchannels,additionalHLTprocessingresources,reliability
• SeetalkfromFransMeijersonSaturday
TRAC2011‐H.W.K.Cheung 26
• Additionalupgrades
• Beaminstrumentationandluminositymonitoring,includesR&Donsuitabledetectors,andupdatestocavernsimulation
• LotsofworkonCMScommonsystems,infrastructureandfacilities
• E.g.experimentalbeampipe,safetysystems,utilities,shielding
• WehaveproducedaPhase1TechnicalProposaldocumentwithsomedetails
SomeWordsontheSchedule
TRAC2011‐H.W.K.Cheung 27
• “Old” 10 year technical Plan from July 2010
• Real schedule likely to change a number of times
SchedulewillbeDrivenbyPhysics
• New draft 10 year plan (Steve Myers, 3/8/2011 SLHC-PP)
TRAC2011‐H.W.K.Cheung 28
LHC Ion
Ion
Injectors
LHC
Injectors
J J A S O N DX‐Masmaintenance
S O N D J F M A MD J AM A M J J A S O ND J F J F M A M JM A M J J A S O NJ J A S O N D J FJ F
SPSupgrade
2016 2017 2018M A M J J A S O N D J F M A M
2019 2020 2021
X‐Masmaintenance
X‐Masmaintenance
N DM J J A S ON D J F M AM J J A S ON D J F M AM J J A S ON D J F M AM J J A S ON D J F M AA M J J A S ON D J F M AM J J A S O
20162010 2011 2012 2013 2014 2015M J J A S ON D J F M
LS1Ion Ion Ion
?SPS‐ LINAC4connection&?PSB energyupgrade
IonLS2 Ion
Machine:Collimation&prepareforcrabcavities &RFcryosystem
ATLAS:nwpixeldetect.‐ detect.forultimateluminosity.
ALICE ‐ Innervertex system
CMS ‐ NewPixel.NewHCALPhotodetectors. CompletionofFWDmuonsupgrade
LHCb ‐ fulltriggerupgrade,newvertexdetectoretc.
Machine:SpliceConsolidation&CollimationinIR3
ATLAS ‐ Consolidation andnewforwardbeampipes
ALICE ‐ detectorcompletion
CMS ‐ FWDmuonsupgrade+Consolidation &infrastrastructure
LHCb ‐ consolidations
SPS‐ LINAC4connection&PSB energyupgrade
Ion
Ion
Ion
LS3Ion
Machine‐ maintenance&
ATLAS‐ Newinnerdetector
ALICE‐ Secondvertexdetectorupgrade
CMS‐ NewTracker
X‐masm
aintenance
?Cryo‐collimationpoint
LS1(LongShutdown1)
LS2(LongShutdown2)
LS3(LongShutdown3)
New beampipe, PLT DT electronics relocation, Fwd mu (CSC4,RE4, ME1/1), HO SiPM, HF PMT, CASTOR
“driven by expts” (2019?) HB/HE SiPM and segmentation, Pixel replacement, Trigger, DAQ Alsoexpectto
usetechnicalstops(wintershutdowns)
Phase2UpgradeR&D
TRAC2011‐H.W.K.Cheung 29
threshold [GeV/c]T
p
10 20 30 40 50 60
Ra
te [
Hz]
1
10
102
103
104
105 generator
L1
L2
L2 + isolation (calo)L3
L3 + isolation (calo + tracker)
SinglemuonL1triggerat5×1035cm‐2s‐1needstrackinginformation;motivatesL1trackingtrigger
For1034cm‐2s‐1
• BuildsonPhase1upgradework
• Replacetrackingsystemtohandle5×1034cm‐2s‐1and3000`b‐1;includesproducingL1tracktrigger
• R&Donsensors,ASICs,datalinks,powerdistribution,CO2cooling,triggerfunctionality
TalksfromSelcukCihangir,LennySpiegel,GiuseppeBroccolo;andpostersbyStefanoMersi,PramodLamichhane• WorkonEB;andforward
EE,HE,HF
• Newmuonelectronics,MPGDsforRPC
• Triggerelectronicsupgrade,increaseL1latencyX2,integrateL1trackingtrigger