Post on 29-Aug-2020
31 October 2005 Mark Oreglia, EFI HEPsem 1
Status of the International Linear Collider Project
Mark Oreglia, University of Chicago
Outline:• Brief Physics Motivation• Acronyms (or what’s happening now)• Accelerator R&D• Detectors• Next Steps (R&D)
Apologies to all the people from whom I stole slides!
31 October 2005 Mark Oreglia, EFI HEPsem 2
ILC means Precision Measurements
These plots from:
Precision of ILC:• pins down models• gives virtual window on high-E• polarization adds even more
31 October 2005 Mark Oreglia, EFI HEPsem 3
Higgs Coupling and Extra Dimensions• ILC precisely measures Higgs interaction strength with standard model particles.
• Straight blue line gives the standard model predictions.
• Range of predictions in models with extra dimensions -- yellow band, (at most 30% below the Standard Model
• The models predict that the effect on each particle would be exactly the same size.
• The red error bars indicate the level of precision attainable at the ILC for each particle
• Sufficient to discover extra dimensional physics.
31 October 2005 Mark Oreglia, EFI HEPsem 4
LHC and the ILC
• There has been much discussion on the relationships between the LHC and the ILC
• The success of the LHC will be a big boost to our field and is probably necessary before ILC start
• Question of concurrent running of LHC and ILC:– So far, no gold-plated argument for this…i.e., could info
from ILC motivate change of LHC trigger?• Indeed, a confusing picture of new physics at LHC would
benefit greatly from ILC data, but this could happen well into LHC’s life
• ILC’s energy reach via precision measurements would probably resolve confusion or lack of new physics at LHC … but that won’t convince funding agencies
• Bottom line: we will need a precision machine to get a more complete picture of LHC’s new physics
31 October 2005 Mark Oreglia, EFI HEPsem 5
Current Progress Towards ILC
• 2002: Formation of ILC Steering Committee– ECFA steering group for Europe– ACFA steering group for Asia– “US” LC Steering group for Americas
• 2003: Funding Agencies for LC (FALC)– Ad hoc group of science ministers and agencies– Ray Orbach and Ian Halliday were major forces
• 2004: Technology choice; First ILC workshop– > 200 accelerator experts from 3 regions
• 2005: Formation of Global Design Effort (GDE)– Barry Barish agrees to head GDE– 2nd ILC workshop at Snowmass last August
31 October 2005 Mark Oreglia, EFI HEPsem 6
Global Design Effort
– The Mission of the GDE • Produce a design for the ILC that includes:
– a detailed design concept, – performance assessments, – reliable international costing, – an industrialization plan , – siting analysis,– detector concepts and scope.
• Coordinate worldwide prioritized proposal driven R & D efforts (to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc.)
31 October 2005 Mark Oreglia, EFI HEPsem 7
The GDE Plan and Schedule
2005 2006 2007 2008 2009 2010
Global Design Effort Project
Baseline configuration
Reference Design
ILC R&D Program
Technical Design
Bids to Host; Site Selection;
International Mgmt
LHCPhysics
31 October 2005 Mark Oreglia, EFI HEPsem 8
GDE – Staffing
• Administrative, Communications, Web staff• Regional Directors (one per region)
– Gerry Dugan: Americas Regional Team (ART)• Accelerator Experts (covering all technical areas)• Senior Costing Engineer (one per region)• Civil/Facilities Engineer (one per region)• Detectors (WWS chairs)• Fill in missing skills (later)
• Total staff size about 20 FTE (2005-2006) about 40 heads.• The internal GDE organization and tasks will be organized
internationally, not regionally
31 October 2005 Mark Oreglia, EFI HEPsem 9
GDE – Near Term Plan
• Schedule– Begin - define Configuration (Snowmass Aug 05) – Baseline Configuration Document (end of 2005)– Baseline under Configuration Control (Jan 06) – Develop Reference Design (end of 2006)– Coordinate the supporting R&D program
• Produce Three volumes –– 1) Reference Design Report; – 2) Shorter glossy version for non-experts and policy makers ; – 3) Detector Concept Report
• Snowmass (Aug 05) first meetings• Frascati (Dec 7-10, 2005) (in conjunction with TESLA
collaboration meeting)• Bangalore, India (March 2006) (in conjunction with LCWS 2006)
31 October 2005 Mark Oreglia, EFI HEPsem 10
New (Snowmass) GDE Groups
• WG1 Parms & layout• WG2 Linac• WG3 Injectors• WG4 Beam Delivery• WG5 High Grad. SCRF• WG6 Communications
• WG1 LET beam dynamics• WG2 Main Linac• WG3a Sources• WG3b Damping Rings• WG4 Beam Delivery• WG5 SCRF Cavity Package• WG6 Communications• GG1 Parameters & Layout• GG2 Instrumentation• GG3 Operations & Reliability• GG4 Cost Engineering• GG5 Conventional Facilities• GG6 Physics Options
Birth of the GDEand Preparation for Snowmass
Introduction of Global Groupstransition workshop → project
31 October 2005 Mark Oreglia, EFI HEPsem 11
Design Approach
• Create a baseline configuration for the machine– Document a concept for ILC machine with a complete
layout, parameters etc. defined by the end of 2005– Make forward looking choices, consistent with attaining
performance goals, and understood well enough to do a conceptual design and reliable costing by end of 2006.
– Technical and cost considerations will be an integral part in making these choices.
– Baseline will be put under “configuration control,” with a defined process for changes to the baseline.
– A reference design will be carried out in 2006. BB proposing to use a “parametic” design and costing approach.
– Technical performance and physics performance will be evaluated for the reference design
31 October 2005 Mark Oreglia, EFI HEPsem 12
Approach to ILC R&D Program
• Proposal-driven R&D in support of the baseline design. – Technical developments, demonstration experiments,
industrialization, etc.• GDE role depends on region; will rank and review
• Proposal-driven R&D in support of alternatives to the baseline– Proposals for potential improvements to the baseline, resources
required, time scale, etc.• Develop a prioritized DETECTOR R&D program aimed at technical
developments needed to reach combined design performance goals– WWS R&D committee will rank, review, and report to GDE– US funding agencies announced they want this input
31 October 2005 Mark Oreglia, EFI HEPsem 13
ILC Siting and Civil Construction
• Civil engineers from all three regions working to develop methods of analyzing the siting issues and comparing sites.
• The current effort is not intended to select a potential site, but rather to understand from the beginning how the features of sites will effect the design, performance and cost
• The design is intimately tied to the features of the site– 1 tunnels or 2 tunnels?– Deep or shallow?– Laser straight linac or follow earth’s curvature in segments?
• GDE ILC Design will be done to samples sites in the three regions – North American sample site will be near Fermilab– Japan and Europe are to determine sample sites by end of 2005
31 October 2005 Mark Oreglia, EFI HEPsem 14
How I spent my summer holiday:
Progress at Snowmass 2005 (GDE’s first footsteps)
>650 participants: Accelerator, Detectors, Physics
http://www-conf.slac.stanford.edu/snowmass05
31 October 2005 Mark Oreglia, EFI HEPsem 15
Snowmass Goals
• To establish a baseline accelerator configuration– And an alternate configuration for future R&D
• To develop the Linear Collider detector studies with precise understanding of the technical details and physics performance of candidate detector concepts, as well as the required future R&D, test beam plans, machine-detector interface and beamlineinstrumentation, cost estimates, and other aspects. – BB has made cost considerations a major priority
• To advance the Linear Collider physics studies, including precision calculations, synergy with the LHC, connections to cosmology andastrophysics, and relationships to the detector design studies.
• To facilitate and strengthen the broad participation of the community in Linear Collider physics, detectors, and accelerators, and engage the greater public in the excitement of this work.
31 October 2005 Mark Oreglia, EFI HEPsem 16
Baseline / Alternative:some definitions
Baseline: a forward looking configuration which we are reasonably confident can achieve the required performance and can be used to give a reasonably accurate cost estimate by mid-end 2006 (→ RDR)
Alternate: A technology or concept which may provide a significant cost reduction, increase in performance (or both), but which will not be mature enough to be considered baseline by mid-end 2006
31 October 2005 Mark Oreglia, EFI HEPsem 17
ILCCommunications
• Launch New ILC Websitewww.linearcollider.org
• “One Stop Shopping”– electronic data management
system (EDMS), news, calendar of events, education and communication
31 October 2005 Mark Oreglia, EFI HEPsem 18
Accelerator R&D:Parameters for the ILC
• Ecm adjustable from 200 – 500 GeV• Luminosity ∫Ldt = 500 fb-1 in 4 years • Ability to scan between 200 and 500 GeV• Energy stability and precision below 0.1%• Electron polarization of at least 80%• Calibrations at Z resonance
• The machine must be upgradeable to 1 TeV
31 October 2005 Mark Oreglia, EFI HEPsem 19
Configuration Parameter Space
31 October 2005 Mark Oreglia, EFI HEPsem 20
main linacbunchcompressor
dampingring
source
pre-accelerator
collimation
final focus
IP
extraction& dump
KeV
few GeV
few GeVfew GeV
250-500 GeV
Major Accelerator Systems
31 October 2005 Mark Oreglia, EFI HEPsem 21
The Hard Questions
Many questions are interrelated and require input from several WG/GG groups … detector groups too!
31 October 2005 Mark Oreglia, EFI HEPsem 22
Design Choices for Baseline• Design Alternatives
– Gradient / Length (30MV/m?, 35MV/m? Higher?)– Tunnel (single? or double?)– Positron Source (undulator? conventional?)– Damping ring (dogbone? small ring?)– Crossing angle (head-on, small angle, large angle)
• Define detailed configuration– RF layout– Lattice layout– Beam delivery system layout– Klystron / modulators– Cryomodule design
• Evolve these choices through “change control” process
31 October 2005 Mark Oreglia, EFI HEPsem 23
Cost Breakdown by Subsystem
cf31%
structures18%rf
12%
systems_eng8%
installation&test7%
magnets6%
vacuum4%
controls4%
cryo4%
operations4%
instrumentation2%
Civil
SCRF Linac
31 October 2005 Mark Oreglia, EFI HEPsem 24
Gradient
31 October 2005 Mark Oreglia, EFI HEPsem 25
How Costs Scale with Gradient
Relative C
ost
Gradient MV/m
2
0
$ l inc ryo
a GbG Q
≈ +
35MV/m is close to optimum
Japanese are still pushing for 40-45MV/m
30 MV/m would give safety margin
C. Adolphsen (SLAC)
31 October 2005 Mark Oreglia, EFI HEPsem 26
Gradients Obtained(Gmax not the whole story!)
Results from KEK-DESY collaboration
must reduce spread (need more statistics)
single
-cel
l m
easu
rem
ents
(in
nin
e-ce
ll ca
vities
)
31 October 2005 Mark Oreglia, EFI HEPsem 27
Gradient
• Baseline recommendation for cavity is standard TESLA 9-cell– 10-yr old design!
• New alternatives (energy upgrade): – Low-loss,– Re-entrant – superstructure
31 October 2005 Mark Oreglia, EFI HEPsem 28
Improved Cavity Shapes
31 October 2005 Mark Oreglia, EFI HEPsem 29
1 vs 2 Tunnels
• Tunnel must contain– Linac Cryomodule– RF system– Damping Ring Lines
• Save maybe $0.5B
• Issues– Maintenance– Safety– Duty Cycle
31 October 2005 Mark Oreglia, EFI HEPsem 30
Examples of Parameter TradeoffDiscussions
Workshop allowed open discussion of new ideas and proposals
W.
31 October 2005 Mark Oreglia, EFI HEPsem 31
Damping Rings: Three variants- no recommendation yet!
3km
6km
17 km ‘dogbone’
Issues:• electron cloud• emittance• aperture• speed of kickers
31 October 2005 Mark Oreglia, EFI HEPsem 32
Positron Source
• Undulator source– Uses main electron beam (150-250 GeV)– Coupled operation – Efficient source – Relatively low neutron activation – Polarisation
• Laser Compton source– Independent polarised source – Relatively complex source – Multi-laser cavity system required– Damping ring stacking required– Large acceptance ring (for stacking) – Needs R&D
• Conventional Source– Single target solution exists– Close to (at?) limits – Independent source
WG3a recommendation for baseline
Will need ‘keep alive source’ due reliability issues
WG3a recommended alternative.
Strong R&D programme needed
Currently on-hold as a backup solution
Pre-damping ring not required
31 October 2005 Mark Oreglia, EFI HEPsem 33
Beam Delivery, MDI
Strawman solution (BCD recommendation)
Appears to work for nearly all suggested parameter sets:Exceptions:• 1 TeV high-luminosity (new parameter set suggested for 20mrad)• 2 mrad extraction has problems with high disruption sets
31 October 2005 Mark Oreglia, EFI HEPsem 34
Beam Delivery System• Baseline recommendation
– Two IRs (20mrad, 2mrad) + 2 detectors– Longitudinally separated halls
• Alternatives 1– Two IRs (20mrad, 2mrad) + 2 detectors with– No longitudinal separation
• Alternative 2– Single IR with push-pull capability for two detectors (cost
favoured)• 10-12mrad crossing angle also being considered• zero-crossing angle being revisited
31 October 2005 Mark Oreglia, EFI HEPsem 35
Case for Two Complementary Detectors
• Confirmation and Scientific Redundancy• Complementarity, Collider Options• Competition• Efficiency, Reliability, Insurance • Sociology, Scientific Opportunity • Historical lessons
We must continue to develop our understanding of the value of two complementary experiments, and to express it convincingly to our colleagues
http://physics.uoregon.edu/~lc/wwstudy/concepts/draft_1.3.doc
We need to decide NOW whether the site footprint should allow for 2 detectorsThere appears to be a strong historical record in support of this, but at what cost?
31 October 2005 Mark Oreglia, EFI HEPsem 36
Discussions on SCRF Test Facilities
• Regional test facilities are needed to enhance the technology base and enable each region to significantly participate in ILC Main Linac and be a possible host of ILC.
• The three regions are working towards developing collaborations on how to build regional test facilities.– TTF Facility (DESY) established facility, 30% allocated to ILC– ILC Test Facility (Fermilab)– STF (KEK)
• International collaborative activities are progressing on– Cavity fabrication, processing and testing to achieve 35 MV/m
at Q ~0.5-1 e10.– Design and fabrication of ILC Cryomodule– LLRF development for ILC– Development and processing of Couplers– Industrial development of the Main Linac components
Critical R&Dto reduce $$$$
31 October 2005 Mark Oreglia, EFI HEPsem 37
• Typically requires factors of two or more improvements in granularity, resolution, etc. from present generation detectors
• Focused R&D program required to develop the detectors -- end of 2005
• Detector Concepts will be used to determine machine detector interface, simulate performance of reference design vs physics goals next year.
Detector Concepts and Challenges- These are NOT LEP Detectors!!!
31 October 2005 Mark Oreglia, EFI HEPsem 38
3 Archetype Physics Topics
• Light Higgs -- tracker– Best recoil mass resolution in Z-> dileptons
• Strong EWSB -- calorimeter– Important to look at WW scattering– W/Z jet separation crucial
• Some SUSY scenarios -- hermeticity– Cosmology “benchmarks” summarized: – “bulk” -> χχ annihilation -> smuon/selectron– “coannihilation” -> χ−sτau annihil. -> staus– Low angle backgrounds
31 October 2005 Mark Oreglia, EFI HEPsem 39
Momentum Resolution
• e+e- ZH ll X• Golden physics channel!
• δ(1/p) = 7 x 10-5/GeV
• 1/10 LEP !!!
• goal: δMµµ <0.1x ΓΖ • δΜΗ dominated by
beamstrahlung
31 October 2005 Mark Oreglia, EFI HEPsem 40
Impact Parameter• δd= 5 µm ⊕ 10/p(GeV) µm• 1/3 SLD !!! • excellent flavor tagging capabilities for charm and bottom
quarks– Need exceptional tagging for reducing combinatorial background in
multi-jets ... – Charge assignment– Asymmetry measurements– (measurement of Higgs BRs not so sensitive!)
• The big question: inner VTX radius– No simple answer – physics reach gains with lever arm and
background suppresion, esp low momentum particles– … thus, low MS, small radius is essential– Needs more validation, but we are talking 1.5 cm radius!– Instrument lifetime issue
31 October 2005 Mark Oreglia, EFI HEPsem 41
(Jet) Energy Resolution
• δE/E = 0.3/√E(GeV)• <1/2 LEP !!!• ∆MDijet ~ ΓZ/W • separation between
e+e- ννWW ννqqqq and e+e- ννZZ ννqqqq
31 October 2005 Mark Oreglia, EFI HEPsem 42
Particle Flow
• reconstruction of multijet final states
( e+e- H+H- tbtb bqqb bqqb)
• Emphasis on combinedsystems now
• System compataibility means fine granularity in calorimeters (1 cm2 !!!)
• Digital mode possible, if backgrounds controllable
31 October 2005 Mark Oreglia, EFI HEPsem 43
Particle / Energy Flow• The energy in a jet is: 60% charged particles; 30% γ ;10%KL,n
• Reconstruct 4-vectors of individual particles avoiding double counting
Charged particles in tracking chambersPhotons in the ECALNeutral hadrons in the HCAL / ECAL
granularity more important than energy resolution
γ
KL,n
π
e
• need to separate energy deposits from different particles
• Jet energy resolution: σjet2 = σch
2 + σγ2 + σnh
2 + σconfusion2
•small X0 and RMoliere : compact showers
•high lateral granularity D ~ O(RMoliere)
•large inner radius L and strong magnetic field
•Discrimination between EM and hadronic showers
•small X0/λhad; longitudinal segmentation
31 October 2005 Mark Oreglia, EFI HEPsem 44
Hermeticity
• hermetic down to θ = 5 mrad
• Important physics with missing energy topologies (SUSY , extra-dim, Higgs, ...)
• Background issues– Ability to veto low-pT particles– Crossing angle optimization
• Excellent physics motivation: SUSY-stau
31 October 2005 Mark Oreglia, EFI HEPsem 45
IR-Related Issues• Good measurements in the low-angle region
– Need to make pT cuts for physics analyses– Need to mask and reduce occupancies in low angle region– Need convincing? See Bambade’s summary of X-angle mtg
• Beam-beam interaction• broadening of energy distribution (beamstrahlung)• ~5% of power at 500 GeV• backgrounds• e+e- pairs• radiative Bhabhas• low energy tail of disrupted beam• neutron “back-shine” from dump• hadrons from gamma-gamma
31 October 2005 Mark Oreglia, EFI HEPsem 46
The Problem from e-pairs
Hits/bunch train/mm2 in VXD,and photons/train in TPC
pairs
31 October 2005 Mark Oreglia, EFI HEPsem 47
Beam Energy Measurement
• need to know <E>lumi-weighted •• Some analyses require better than 0.1%Some analyses require better than 0.1%• techniques for determining the lumi-weighted
<ECM>:energy spectrometers Bhabha acolinearity
• Other possibilities :γZ, ZZ and WW events; use existing Z and W massutilize Bhabha energies in addition to Bhabha acolµ-pair events; use measured muon momentum
•• 200 200 ppmppm feasible; 50 feasible; 50 ppmppm a difficult challengea difficult challenge
Top-mass: need knowledge of E-spread FWHM to level of ~0.1%
31 October 2005 Mark Oreglia, EFI HEPsem 48
Crossing Angle Impact on
Forward Detector
31 October 2005 Mark Oreglia, EFI HEPsem 49
Time Structure:
Event rates: Luminosity: 3.4x1034 cm-2 s-1 (6000xLEP)e+e- qq,WW,tt,HX 0.1 / train e+e- γγ X:~200 /Train
Background from Beamstrahlung:6x1010 γ/BX 140000 e+e-/BX + secondary particles (n,µ)
950 µs 199 ms 950 µs
2820 bunches
5 Bunch Trains/s ∆tbunch=337ns
But still: 600 hits/BX in Vtx detector6 tracks/BX in TPC E=12GeV/BX in calorimetersE 20TeV/BX in forward cals.
Need Large B field and shielding
High granularity of detectorsand fast readout for stablepattern recognition and event reconstruction
Rates in the Detectors
31 October 2005 Mark Oreglia, EFI HEPsem 50
Summary of MDI Issues• Detector designers need input from MDI experts:
– Minimum VTX radius (smaller than you’d like!)– Masking optimization and best model (MC tool) for backgrounds– Feasibility of crossing angle options
• Detector designers need MDI experts to appreciate:– Need for small on systematic <E>lumi– Need for reduction in low-angle background– Need for diagnostic instrumentation
• This talk continues with a description of current designs– New tools are causing all to be rethought– I’ve completely neglected the special requirements of a detector
optimized for γ−γ or e-γ collisions• Even worse low-angle background problems
31 October 2005 Mark Oreglia, EFI HEPsem 51
Comparison of 3 Concepts(thanks to Y. Sugimoto)
SD TESLA GLD
Main Tracker EM Calorimeter H Calorimeter Cryostat Iron Yoke / Muon System
5 m
•Very large R•Jet chamber or TPC•Scintilator/W-Pb-Fe
•Moderate R•TPC tracker•SiW ECAL
•Si tracking and ECAL•Small R•Smallest granularity
31 October 2005 Mark Oreglia, EFI HEPsem 52
Following the GDE Timeline
machine
end of 2005Baseline Configuration Document
end of 2006Develop Reference Design Rpt
3 volumes: i.) RDR (machine)ii.) Detector Concept Reportiii.) Exec Summary
detectors
R&D ReportDetector Outlines (Mar, 2006)→ Detector Concept Report
31 October 2005 Mark Oreglia, EFI HEPsem 53
Detector Outline Documents• To be completed in Spring 2006 by each detector
concept team, and submitted to WWS.
• Contents– Description of the detector concept– Performance estimates wrt physics
benchmarks– Required R&Ds and their status– Rough costing estimate
• Real detector CDR in 2007
• … and how do we get there? ….
31 October 2005 Mark Oreglia, EFI HEPsem 54
Detector R&D
• WWS has created a Detector R&D Panel – collect information on projects world-wide – strengthen coordination and prioritization
• R&D Panel preparing the R&D report to accompany the GDE machine Baseline Configuration Documentlate this year – supported by concepts and R&D teams
• Test beam planning
31 October 2005 Mark Oreglia, EFI HEPsem 55
University Detector R&D in US
This year was the third year of support for detector R&D from the agencies, organized by the USLCSG and the ALCPG
FY05 LCDRD funding:$700,000 from DOE$117,000 from NSF
Proposal process for FY06 will begin in the fall
24 projects25 universities
31 October 2005 Mark Oreglia, EFI HEPsem 56
Extra Slides: Detectors
31 October 2005 Mark Oreglia, EFI HEPsem 57
Basic TESLA Detector Concept
No hardware trigger, dead time freecontinous readout for complete bunch train (1ms)
Zero suppression, hit recognition and digitisation in FE electronics
Large gaseous centraltracking device (TPC)
High granularitycalorimeters
High precisionmicrovertex detector
All inside magnetic fieldof 4 Tesla
31 October 2005 Mark Oreglia, EFI HEPsem 58
Overview of tracking system
Central region:Pixel vertex detector (VTX)Silicon strip detector (SIT)Time projection chamber (TPC)
Forward region:Silicon disks (FTD) Forward tracking chambers (FCH)(e.g. straw tubes, silicon strips)
• B=4T, RTPC=1.7m: momentum resolution δ(1/p) < 7 x 10-5 /GeV
• American version has larger TPC outer radius (2m), lower B (3T)
• looking at various TPC pad designs and readout
31 October 2005 Mark Oreglia, EFI HEPsem 59
Vertex Detector: Conceptual Design5 Layer Silicon pixel detector
•Small R1: 15 mm (1/2 SLD)
•Pixel Size:20x20µm2 σPoint =3 µm
•Layer Thickness: <0.1%X0 suppression of γ conversions –ID of decay electronsminimize multiple scattering
800 million readout cells
Hit density: 0.03 /mm2 /BX at R=15mm pixel sensors
Read out at both ladder ends in layer 1:frequency 50 MHz, 2500 pixel rows
complete readout in: 50µs ~ 150BX
<1% occupancyno problem for track reconstruction expected
Impact parameter: σd ~R1 σpoint
31 October 2005 Mark Oreglia, EFI HEPsem 60
Calorimeter Conceptual DesignECAL and HCAL inside coil
large inner radius L= 170 cmgood effective granularity
∆x~BL2/(RM ⊕ D) 1/p
∆x distance between charged and neutral particle at ECAL entrance
•ECAL: SiW, •40 layers/24Xo/0.9lhad, 1cm2 lateral segmetation• σE/E = 0.11/√E(GeV) ⊕ 0.01
•HCAL: many options• scintilator tiles, analog or digital• steel-scintillator sandwich
31 October 2005 Mark Oreglia, EFI HEPsem 61
Forward Tracking
FTD: 7 Disks 3 layers of Si-pixels 50x300µm2
4 layers of Si-strips σrφ= 90µm
FCH: 4 LayersStrawtubes or Silicon strips(double sided)
250 GeV µ
31 October 2005 Mark Oreglia, EFI HEPsem 62
Forward Calorimeters
LCAL: Beam diagnostics and fast luminosity (28 to 5 mrad) ~104 e+e— pairs/BX 20 TeV/BX 2MGy/yrNeed radiation hard technology: SiW, Diamond/W Calorimeter or Scintillator Crystals
LAT: Luminosity measurement from Bhabhas (83 to 27 mrad) SiW Sampling Calorimeteraim for ∆L/L ~ 10-4 require ∆θ = 1.4 µrad
TDR version of mask L* = 3 m
Tasks:
Shielding against background
Hermeticity / veto
f
f
e
e
31 October 2005 Mark Oreglia, EFI HEPsem 63
SiD Design Starting Point(Thanks to Marty Breidenbach, John Jaros)
B = 5T Recal = 1.25m Zecal = 1.74m
31 October 2005 Mark Oreglia, EFI HEPsem 64
The SiD Rationale
Premises:particle flow calorimetry will deliver the best possible performance
Si/W is the right technology for the ECAL
Excellent physics performance, constrained costs
Si/W calorimetry for excellent jet resolution
therefore…
• Limit Si/W calorimeter radius and length, to constrain cost
• Boost the B field to recover BR2 for particle flow, improve momentum resolution for tracker, reduce backgrounds for VXD
• Use Si microstrips for precise tracking
31 October 2005 Mark Oreglia, EFI HEPsem 65
Gaseous or Silicon Central Tracking?gaseous silicone e H0 A 0 b b b b
advantages of gaseous tracking: many pointssimple pattern recognitionredundancy
“but be careful with these comparisons!”This is something of an aesthetic argument
31 October 2005 Mark Oreglia, EFI HEPsem 66
ECAL
31 October 2005 Mark Oreglia, EFI HEPsem 67
Si Detector/ Readout ChipReadout ~1k pixels/detectorwith bump-bonded ASIC
Power cycling – only passive cooling required
Dynamic range OK(0.1 - 2500 mip)
Pulse Height and Bunch Label buffered 4 deep to accommodate pulse train
31 October 2005 Mark Oreglia, EFI HEPsem 68
HCAL• Inside the coil• Rin= 1.42m; Rout= 2.44m• 4λ Fe (or W, more compact)
2cm Fe, 1cm gap• Highly segmented
1x1 cm2 – 3x3 cm2
~ 40 samples in depth• Technology?
RPCScint TileGEM
S. Magill (ANL)…many critical questions for the SiD Design Study: thickness? Segmentation? Material? Technology?
31 October 2005 Mark Oreglia, EFI HEPsem 69
VXDTesla SiD
Shorten barrel, add endcaps.Shorten Barrel CCDs to 12.5 cm (vs. 25.0cm)add 300 µm Si self-supporting disk supporting disk endcapsendcaps(multiple (multiple CCDsCCDs per disk)per disk)
This extends 5 layer tracking over max Ω, improves forward pattern recognition.
improve Ω Coverage, improve σimpact param5 CCD layers .97 (vs. .90 TDR VXD)4 CCD layers .98 (vs. .93 TDR VXD)
Readout speed and EMI are big questions.
-0.2
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
31 October 2005 Mark Oreglia, EFI HEPsem 70
Global Large Detector
235 280430
425 845
700
450
375350
210205
40 3540
Main Tracker EM Calorimeter H Calorimeter Cryostat Iron Yoke / Muon System
QC1 SX765
31 October 2005 Mark Oreglia, EFI HEPsem 71
Basic design concept• Detector optimized for Particle Flow Algorithm (PFA)
• Large/Huge detector concept
– GLC detector as a starting point– Move inner surface of ECAL outwards to optimize for PFA– Larger tracker to improve δpt/pt
2
– Re-consider the optimum sub-detector technologies based on the recent progresses
• Different approaches
– B Rin2 : SiD
– B Rin2 : TESLA
– B Rin2 : Large/Huge Detector
31 October 2005 Mark Oreglia, EFI HEPsem 72
Merits and demerits of Large/Huge detector
• Merits– Advantage for PFA– Better pt and dE/dx resolution for the main tracker– Higher efficiency for long lived neutral particles (Ks, Λ, and
unknown new particles)• Demerits
– Cost ? – but it can be recovered by• Lower B field of 3T (Less stored energy)• Inexpensive option for ECAL (e.g. scintillator)
– Vertex resolution for low momentum particles• Lower B requires larger Rmin of VTX because of beam background
δ(IP)~5 ⊕ 10/(pβsin3/2θ) µm is still achievable using wafers of ~50µm thick
31 October 2005 Mark Oreglia, EFI HEPsem 73
Parameters compared
9.77.15.7BL2.5
1.2 e-4
220
150
2.0
0.4
1.8
9.86
3.75
3
GLD
1.5e-43.6e-5δpt/pt2
2005Nsample
1507σ(µm)
1.621.25Rmax(m)
0.360.2Rmin (m)Main Tracker
2.31.4Estored(GJ)
9.25.8L(m)
3.02.48Rin(m)
45B(T)Solenoid
TESLASiD
31 October 2005 Mark Oreglia, EFI HEPsem 74
Paramters (cont’d)
(W/Sci)W/SiW/SiType
1.41.31.18t (m)
6.05.25.5λE+HCAL
272421X0
14521311822BZ2/Rmeff
2.82.831.72Z (m)
817462448BRin2/Rm
eff
16.224.418Rmeff (mm)
13.211.38.1BRin2
2.11.681.27Rin (m)ECAL
GLDTESLASiD