ILC Detector R&Ds and Design
Toward detectors and collaborations that realize and maximize the physics output of ILC
Hitoshi YamamotoTohoku University
ICFA seminar, Daegu, Sept. 29, 2005
ILC Parameters
■ 1st stage Energy 200→500 GeV 500 fb-1in first 4 years + 500 fb-1in next 2 years
■ 2nd stage Energy upgrade to ~1TeV 1000 fb-1in 3-4 years
■ Energy scan + e polarization■ Options
eeeGiga-Z, e+ polarization
(http://www.fnal.gov/directorate/icfa/LC_parameters.pdf)
ILC Physics
e.g. Higgs coupling measurements
SM Higgs : coupling mass
Higgs Couplings : Deviations from SM(By S. Yamashita)
SUSY (2 Higgs Doulet Model)
Extra dimension(Higgs-radion mixing)
ILC Detector Performance Goals
■ Vertexing ~1/5 rbeampipe,~1/30 pixel size (wrt LHC)
■ Tracking ~1/6 material, ~1/10 resolution (wrt LHC)
■ Jet energy (quark reconstruction) ~1/2 resolution (wrt LHC)
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σ ip = 5μm ⊕10μm / psin3 / 2 θ
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σ(1/ p) = 5 ×10−5 /GeV
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σE / E = 0.3/ E(GeV)
(http://blueox.uoregon.edu/~lc/randd.pdf)
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(h → bb ,cc ,τ +τ −)
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(e+e− → Zh → l +l −X; incl. h → nothing)
b, c tagging by vertexing
Pixel vertex detector
4-layer 0.3 % X0/ layer rbp = 2 cm conservative design 5-layer 0.1 % X0/ layer rbp = 1 cm agressive design (~goal resolution)
e+e → ZH Recoil mass resolution
■ Good momentum resolution of ~5x10-5 is required (not a luxuary). Not limited by the beam energy spread.
Only Z→l+l- detected : Higgs decay independent
Jet(quark) reconstruction
■ With , Z/Wjj can be reconstructed and separated
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σE / E = 0.6 / E(GeV)
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σE / E = 0.3/ E(GeV)
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e+e− → νν WW ,νν ZZ
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W /Z → jj
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σE / E = 0.3/ E
(Strong EWSB)
PFA (Particle Flow Algorithm)
■ Many other important modes have 4 or more jets : e.g.
Higgs self-coupling : 6 jets
Top Yukawa coupling : 8 jets
WW* branching fraction of Higgs : 4 jets+missing
■ How to achieve for jet ?■ Basic idea : PFA
Use trackers for charged particles Use ECAL for photon The rest is assumed to be neutral hadrons (ECAL+HCAL)
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e+e− → Zhh → (qq )(qq )(qq )
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σE / E = 0.3/ E€
e+e− → tt h → (bqq )(b qq )
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e+e− → Zh → (qq )(qq )(l ν )
Red : pionYellow : gammaBlue : neutron
e+
e-
Z→qq (by T. Yoshioka)
- Gamma Finding
Red : pionYellow : gammaBlue : neutron
gamma
- Track Matching
Red : pionYellow : gammaBlue : neutron
Remaining hits are assumedto be neutral hadrons.
Red : pionYellow : gammaBlue : neutron
PFA : major soruce = confusion
■ Using typical values
■ ... and ignoring confusion,
■ Confusion is dominant even for the goal of
■ → fine segmentation , large radius : cost!
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σ jet2 = σ ch
2 + σ γ2 + σ nh
2 + σ confusion2
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σ ch << σ γ ,nh , σ γ / Eγ =11% / Eγ , σ nh / Enh = 34% / Enh
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σ jet / E jet =12% / E jet
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σE / E = 30% / E
Beampipe radius
■ Stay-clear for the soft e+e- pair background
R ~ 1/B1/2
■ Larger ECAL radius → larger solenoid radiu
s → lower B (cost!) → larger beampipe R → worse vertexing
■ Where is the optimum?IP
Major Detector Concept Studies(the parameters are the current defaults - may change)
■ SiD (American origin) Silicon tracker, 5T field SiW ECAL 4 ‘coordinators’ (2 Americans, 1 Asian, 1 European)
■ LDC (European origin) TPC, 4T field SiW ECAL (“medium” radius) 6 ‘contact persons’: (2 Americans, 2 Asians, 2 Europeans)
■ GLD (Asian origin) TPC (+Silicon IT), 3T field W/Scintillator ECAL (“large” radius) 6 ‘contact persons’: (2 Americans, 2 Asians, 2 Europeans)
+ vertexing near IP
ECAL/HCAL inside coil
Detector Concepts
■ 4th concept proposed at Snowmass 05 Based on dual-readout compensating cal.
■ Requests from WWS for new concept (as of 2005,9)
Contact person(s) Provide representatives for panels (R&D panel, MDI panel, Costing panel) Produce “detector outline document” by end Feb. 2006
WWS (Worldwide Study)
■ Started in 1998 (Vancouver ICHEP)■ 6 committee members from each of 3 regions■ 3 co-chairs - now members of GDE
C. Baltay → J. Brau D. Miller → F. Richard S. Komamiya → H. Yamamoto
■ Tasks (in short) Recognize and coordinate detector concept studies Register and coordinate detector R&Ds Interface with GDE Organize LCWS (1 per year now)
Detector Outline Document
■ Document that precedes CDR■ Contents (~100 pages total)
Introduction Description of the concept Expected performances for benchmark modes Subsystem technology selections Status of on-going studies List of R&Ds needed Costing Conclusion
Detector Timeline
(2005 end) Acc. Configuration Document
Detector R&D report
(2006,2 end) “Detector outline documents” (one for each detector concept)
(2006 end) Acc. Reference Design Report
Detector CDR (one document)
(~2008) LC site selection Collaborations form
~Site selection + 1yr Global lab selects experiments.
Accelerator Detector
#BDS (beam delivery system) and crossing angles
20mrad xing simpler and better understood now Two BDSs →More constraints on linac One BDS with 10-12mrad xing? Machine simulation : more background for 2mrad Detector simulation : more background for 20mrad Baseline configuration to be determined
#IR, #detectors (at ILC startup)?■ Roughly in rising/falling order of preference for acc./det. p
eople, (iIR: instrumented IR, nIR: non-instrumented IR)
2 iIRs/ 2 detectors 1 iIR/ 2 detectors (push-pull) + 1 nIR 1 iIR/ 2 detectors (push-pull) 1 iIR/ 1 detector (push-pull capability) 1 iIR/ 1 detector + 1 nIR 1 iIR/ 1 detector
■ #det panel of WWS (chair: J. Brau) Produced a report (http://blueox.uoregon.edu/~lc/wwstud
y)
WWS Panels
WWS
parameter
R&D
MDI
benchmark
costing
software
........
done
~done
R&D Panel■ Charge:
Survey and prioritize R&Ds needed for ILC experiments (NOT individual proposals)
Inputs are from R&D collaborations and concept studies
Register and facilitate regional review processes■ Chair: C. Damerell ■ Outputs:
Web links to R&Ds https://wiki.lepp.cornell.edu/wws/bin/view/Projects/WebHo
me Detector R&D report (end 2005)
Horizontal and Vertical collaborationsIt is something like this : (detail may not be accurate)
Vertexing 1 train = ~3000 bunches in 1ms, 5 Hz Typical pixel size ~ (20m)2 → occupancy is too high if integrate
over 1 train. No solution to bunch id each hit so far. Then what?
■ Readout during train ( ~20 times) Standard pixel size - MAPS, CPCCD, DEPFET, SOI
■ Readout between train Standard pixel size ( ~20 time slices stored on-pixel)
◆ Store in CCD - ISIS◆ Store in capacitors - FAPS
Fine pixel size (~1/20 standard)◆ No Bunch id - FPCCD ◆ Bunch id - CMOS (double pixel sensor)
No demonstrated solution yet. (apology for not covering all...)
CPCCD (column-parallel CCD)
■ RAL■ Readout each column separately■ 50MHz would readout 5cm 20
times per train■ Diffusion : multi hit while shifting
→ fully depleted CCD?■ Prototype sensor (CPC1) tested w/
>25 MHz readout.■ Clock drive is challenging.■ Readout chip made (CPR1)
Operation verified (w/bugs to fix)■ New sensor/readout fabricated
(CPC2/CPR2) and under tests.
MAPS (Monolithic Active Pixel Sensor)
■ IReS,GSI,CEA (+SUCIMA coll.)■ Use the epi-layer of commercia
l processes - small signal (a few 10s e)
■ 1Mrad OK (SUCCESOR1)■ 1012n/cm2 OK, 1013e/cm2 OK (MIMOSA9)■ 3 sensors thinned to 50m
■ CP,CDS works(MIMOSA8), but not fast - readout transversely.
■ Also try FAPS-like scheme (MIMOSA12)
5mm 2mm
Inner layer
sensor ADC/clusterng
ADC count 55Fe
Before&after 1Mrad
ISIS (In-situ Storage Image Sensor)
Small CCD on each pixel (~20 cells) - charge is
shifted into it 20 times per trainImmune to EMITechnology exists as ultra-high-speed cameraPrototype now being made (E2V)
To column load
Source followerReset transistor Row select transistor
p+ shielding implant
n+buried channel (n)
storage
pixel #1
storage
pixel #20 sense node (n+)
Charge collection
row select
reset gate
VDD
p+ well
reflected charge
reflected charge
photogate
transfer
gate
output
gate
High resistivity epitaxial layer (p)
FAPS (Flexible Active Pixel Sensor)
Pixels 20x20 m2
10 storage cells per pixel
(20 in the real sensor)First prototypes in 2004Source test done
FPCCD (KEK)
■ Fine-pixel CCD (5m)2 pixel Fully-depleted to suppress
diffusion Immune to EMI CCD is an established technology Baseline for GLD
Fully-depleted CCD exists (Hamamatsu : astrophys.)
Background hits can be furhter reduced by hit pattern (~1/20)
No known problems now Want to produce prototype in 2
006 (Funding!)
CMOS (double pixel sensor)
■ Yale, Oregon■ 2 pixel sensors on top of each ot
her - 5x5m2 (micro) and 50x50m2 (macro)
■ Macro pixel triggers and times (bunch id) hits - up to 4 hits stored on pixel.
■ Micro pixels store analog signal.■ Time and ADC data are read out
between trains. ■ Only micro pixels under hit macr
o pixels are queried.■ Two sensors in one silicon, or bump-bonded.■ Conceptual design being worked
with Sarnoff.50m
Trackers
■ Two main candidates TPC - central tracker for GLD, LDC
◆ ~200 hits/track σm/hit Silicon strip - central tracker for SiD
◆ ~5 hits/track with much better σ◆ Also used as
◆ Inner/forward tracker for GLD, LDC◆ Endcap tracker for GLD◆ Outer tracker (of TPC) for LDC
TPC■ Endplate detectors
Wires - conventional◆ Amplification at wires only◆ Signal is induced on pads - slow collection◆ Strong frame needed - endplate material◆ Wires can break
MPGD (Multi-pixel Gas Detector) - R&D items◆ Amplification where drift electrons hit (w/i ~100m)◆ Directly detect amplified electrons on pads - fast◆ Ion feeback suppressed
◆ GEM (Gas Electron Multiplier)◆ 2-3 stages possible - discharge-safer(?)
◆ MicroMEGAS (Micro Mesh Gas detector)◆ 1 stage only - simpler
MicroMEGAS
■ Micromesh with pitch~50m■ Pillar height ~ 50-100m■ Amplification between mesh an
d pads/strips■ Most ions return to mesh.
S1
S2
σ
~50m
MicroMEGAS
■ Micromesh with pitch~50m■ Pillar height ~ 50-100m■ Amplification between mesh an
d pads/strips■ Most ions return to mesh.
S1
S2
σ
~50m
GEM■ Two copper foils on both sides
of kapton layer of ~50m thick■ Amplification at the holes■ Gain~104 for 500V■ Can be used multi-staged■ Natural broadening can help ce
nter-of-gravity technique.
p~140m
p~60m
ILC TPC R&D groups~70 active people worldwide
DESY
Aachen
Victoria
MPIKEK
Sacley-Orsay
KerlsruheBerkeleyNovosibirskCarletonCornell.....
Interconnected
TPC R&D results
• Now 3 years of MPGD experience gathered. MPGDs compared with wire
• Gas properties rather well understood (dirft velocity, diffusion effect ~ MC)
• Diffusion-limited resolution seems feasible
• Resistive foil charge-spreading demonstrated
• CMOS RO chip demonstrated• Design work starting for the
Large Prototype (funded by EUDET)
GEM vs wire
Charge spreading by resistive foil
Silicon Tracker R&Ds■ DSSD in-house fabrication in Kor
ea Characterized. S/N = 25 Radiation test in progress Hybrid is produced
■ Long-ladder R&D (SantaCruz) Readout chip LSTFE for long and
spaced bunch train. Being tested.
Backend architecture defined Long ladders being assembled
■ SILC collaboration 10-60cm strip length S/N = 20-30 for 28cm (Sr90), O
K New front end chip being tested ~OK. Next : power cycling Ladder assembly prototype soon
Calorimeters
E
%40~
■ Critical part of PFA
■ ‘Realistic’ PFA Full shower simulation Clustering Photon finding Track matching Achieved ~40%/E1/2 for the 3 concepts
■ Starting to be useful for detector optimization
Analog vs digital HCAL readout Segmentation However, not quite mature yet to be
conclusive
■ Large international collaboration : CALICE Jet energy resolution at Z→qq
ECAL■ Silicon/W
High granularity (~1cm2 or less) and stable gain. Cost : $2-3/cm2 for Si. How far can it go down?
CALICE prototype (1cm2 cell) beam test SLAC/Oregon/UCDavis/BNL silicon wafer (4x4mm2)
ECAL■ Scintillator/W
Cheaper and larger granurarity (3x3 - 5x5cm2) Scintillator strips may be cost-effective way for granurarity (1cm x Ycm) Read out by fibre + PMT or SiPM/MPC
Japan/Korea/Russia Colorado : staggered cells (5x5cm2)
■ SiPM (invented in Russia) ~100 cells in 1mm2
Limited Geiger mode High B field (5T) OK Gain ~ 106 ; no preamp Fast σ~ 50ps Quite cheap Noisy? Temperature dependence Steep bias valtage dependenc
e
HAMAMATSU MPC(Multipixel Photon Counter)Sees ~60 pe’s at room temp.
HCAL
■ Analog : Scintillator (CALICE) Modest granurarity (3x3cm2 u
p) SiPM readout MINICAL prototype tested with
100 SiPM - Same resolution as PMT
2 cm steel
0.5 cm active
HCAL■ Digital (CALICE)
Fine granurarity (~1x1cm2) 1 bit readout GEM and RPC w/ pad readout Common readout electronics Understood well - ready for 1m3
prototype
Signal PadMylar sheet
Mylar sheet Aluminum foil
1.1mm Glass sheet
1.1mm Glass sheet
1.2mm gas gap
-HV
GND
GEMRPC
Calorimeter R&Ds
■ Si-Scintillator hybrid for ECAL Cost-performance optimization
■ Crystal for ECAL Focus on energy resolution
■ DREAM Dual readout of dE/dx (scintillat
or) and Cerenkov (quartz fibre) Ideal compensation to obtain ve
ry good hadron energy resolution Basis for the 4-th concept Challenge : ILC implementation
Other subsystems
■ Muon system is probably easy in concept but difficult in practice (large system - support, etc.)
■ Solenoid and compensation coil (DID - for large xing angle) : non-trivial problem to realize, and DID is a problem to solve for trackers and bkg.
■ Forward regions (endcap regions) are important for t-channel productions such as
■ Very forward regions (FCAL, BCAL) are critical for tagging electrons for SUSY pair creations.
■ With the long train, DAQ is not a trivial problem
■ Beam instumentations such as pair background detector play important roles in machine operation/tuning
Just as importnat as what has been shown
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e+e− → νν h
Concluding Remarks
■ Too many R&Ds too cover : apology for those not covered. Refered to the R&D report to be produced ~ end 2005.
■ Resolutions much better than past is not luxuries, but required for balanced investment in ILC.
■ With EUDET ($7M over 4 years), detecor R&D in Europe is now reasonably funded (only for ‘infrastructures), but severely underfunded in Americas and Asia.